MCQ Questions – Page 45

MCQ Questions for Class 8 Science Chapter 13 Sound with Answers

Sound Class 8 MCQ Online Test With Answers Questions

October 18, 2024

Check the below Online Education NCERT MCQ Questions for Class 8 Science Chapter 13 Sound with Answers Pdf free download. MCQ Questions for Class 8 Science with Answers were prepared based on the latest exam pattern. We have provided Sound Class 8 Science MCQs Questions with Answers to help students understand the concept very well. https://ncertmcq.com/mcq-questions-for-class-8-science-with-answers/

You can refer to NCERT Solutions for Class 8 Science Chapter 13 Sound to revise the concepts in the syllabus effectively and improve your chances of securing high marks in your board exams.

Class 8 Science Chapter 13 MCQ With Answers

Science Class 8 Chapter 13 MCQs On Sound

Choose the correct option.

Sound Class 8 MCQ Question 1.
The voice box is also called as
(a) stomach
(b) heart
(c) larynx
(d) mouth

Answer

Answer: (c) larynx

Sound MCQ Class 8 Question 2.
Sound is a kind of
(a) work
(b) energy
(c) force
(d) pressure

Answer

Answer: (b) energy

Class 8 Science Chapter 13 MCQ Question 3.
The hearing range of human ear is
(a) 20 Hz to 20,000 Hz
(b) less than 20 Hz
(c) more than 20,000 Hz
(d) 20 Hz to 25,000 Hz

Answer

Answer: (a) 20 Hz to 20,000 Hz

Class 8 Sound MCQ Question 4.
Pitch of sound is determined by its
(a) frequency
(b) speed
(c) amplitude
(d) loudness

Answer

Answer: (a) frequency

MCQ On Sound Class 8 Question 5.
The frequency of subsonic sound is
(a) more than 20 Hz
(b) 100 Hz
(c) less than 20 Hz
(d) more than 20,000 Hz

Answer

Answer: (c) less than 20 Hz

MCQ Of Sound Class 8 Question 6.
Cochlea is a part of
(a) hearing organ
(b) sound producing organ
(c) muscular organ
(d) air pollution

Answer

Answer: (a) hearing organ

Class 8 Science Sound MCQ Question 7.
1 hertz is equal to
(a) 1 vibration per minute
(b) 10 vibrations per minute
(c) 60 vibrations per minute
(d) 600 vibrations per minute

Answer

Answer: (c) 60 vibrations per minute

MCQ Questions For Class 8 Science Chapter 13 Question 8.
Sound cannot travel through
(a) air
(b) water
(c) air
(d) vacuum

Answer

Answer: (d) vacuum

Sound Chapter Class 8 MCQ Question 9.
The sound in the audible range is called
(a) ultrasonic sound
(b) sonic sound
(c) subonic sound
(d) light sound

Answer

Answer: (b) sonic sound

Class 8 Science Ch 13 MCQ Question 10.
Speed is
(a) \(\frac{Distance travelled}{Time}\)
(b) \(\frac{Time}{Distance travelled}\)
(c) Distance travelled × Time
(d) Time + Distance travelled

Answer

Answer: (a) \(\frac{Distance travelled}{Time}\)

Ch 13 Science Class 8 MCQ Question 11.
A pendulum oscillates 20 times in 4 seconds. Find its time period.
(a) 0.05 sec.
(b) 0.001 sec.
(c) 0.2 sec.
(d) 0.1 sec

Answer

Answer: (c) 0.2 sec.

MCQ Sound Class 8 Question 12.
Loudness of sound is determined by
(a) pitch
(b) frequency
(c) amplitude
(d) time period

Answer

Answer: (c) amplitude

Class 8 Science Chapter Sound MCQ Question 13.
The number of vibrations made by a vibrating body in one second is
(a) frequency
(b) noise
(c) loudness
(d) pitch

Answer

Answer: (a) frequency

MCQs On Sound Class 8 Question 14.
The maximum displacement of a body from its mean position is called
(a) amplitude
(b) oscillation
(c) periodic motion
(d) frequency

Answer

Answer: (a) amplitude

MCQ Questions On Sound Class 8 Question 15.
The velocity of sound at 20°C is approximately
(a) 3400 m/sec.
(b) 340 m/sec.
(c) 430 m/sec
(d) 304 m/sec.

Answer

Answer: (b) 340 m/sec.

Question 16.
Sound is produced by
(a) Non-Vibrating objects only
(b) Vibrating and non- vibrating objects
(c) Vibration has no relation to sound
(d) Vibrating objects only

Answer

Answer: (d) Vibrating objects only

Question 17.
Sound cannot travel through
(a) vacuum
(b) air
(c) water
(d) solids

Answer

Answer: (a) vacuum

Question 18.
Vibration is also known as
(a) Vibratory motion
(b) Translatory motion
(c) Oscillatory motion
(d) None of these

Answer

Answer: (c) Oscillatory motion

Question 19.
Frequency is expressed in
(a) Kilometer
(b) Hertz
(c) gram
(d) Degree centigrade

Answer

Answer: (b) Hertz

Question 20.
The number of oscillations per second is called
(a) Amplitude of oscillation
(b) Pitch of oscillation
(c) Frequency of oscillation
(d) None of the above

Answer

Answer: (c) Frequency of oscillation

Question 21.
Above _____ dB the sound becomes physically painful
(a) 60
(b) 40
(c) 120
(d) 80

Answer

Answer: (d) 80

Question 22.
When the amplitude of vibration is large, sound produced is
(a) No sound
(b) feeble
(c) loud
(d) No relation between amplitude and sound

Answer

Answer: (c) loud

Question 23.
Human can hear sound in the range of
(a) 200-2000 Hz
(b) 20-20,000 Hz
(c) 2-20000 Hz
(d) 2000-200000 Hz

Answer

Answer: (b) 20-20,000 Hz

Question 24.
An ultrasound equipment works at frequency
(a) Higher than 20,000 Hz
(b) Higher than 10,000 Hz
(c) Lower than 20,000 Hz
(d) Lower than 10,000 Hz

Answer

Answer: (a) Higher than 20,000 Hz

Question 25.
Voice of man is heavy compared to a woman because
(a) Female vocal cord is longer
(b) Male vocal cord is shorter
(c) Male vocal cord is longer
(d) The concept is not related

Answer

Answer: (c) Male vocal cord is longer

Match the items given in column I suitably with those given in column II.

Column I	Column II
1. Audible frequencies	(a) 10 dB
2. Length of vocal cords in man	(b) 30 dB
3. Ultrasound	(c) 20 mm long
4. Normal breathing	(d) 20 to 20,000 Hz
5. Soft whisper (At 5 m)	(e) Hertz
6. Frequency	(f) Percussion instrument
7. Unpleasant sound	(g) Music
8. Pitch	(h) Produced by bats
9. Tabla	(i) Noise
10. Pleasant sound	(j) Higher frequency

Answer

Answer:

Column I	Column II
1. Audible frequencies	(d) 20 to 20,000 Hz
2. Length of vocal cords in man	(c) 20 mm long
3. Ultrasound	(h) Produced by bats
4. Normal breathing	(a) 10 dB
5. Soft whisper (At 5 m)	(b) 30 dB
6. Frequency	(e) Hertz
7. Unpleasant sound	(i) Noise
8. Pitch	(j) Higher frequency
9. Tabla	(f) Percussion instrument
10. Pleasant sound	(g) Music

Fill in the blanks with suitable word/s.

1. human beings sound is produced by __________.

Answer

Answer: larynx

2. Sound of frequency lower than 20 Hz is called the __________.

Answer

Answer: infrasonic

3. The __________ nerve is also present in the inner ear.

Answer

Answer: auditory

4. Sounds which are unpleasant to the ear is called __________.

Answer

Answer: noise

5. Too much noise in our surroundings that causes discomfort is called __________.

Answer

Answer: noise pollution

6. The speed of sound is maximum in __________.

Answer

Answer: solids

7. Sounds of frequencies higher than 20,000 Hz are called the __________ sound.

Answer

Answer: ultrasonic

8. __________ is the time taken by a vibrating body for one complete vibration.

Answer

Answer: Time period

9. Above __________ the noise becomes physically painful.

Answer

Answer: 80 dB

10. Plantation on the roadside can reduce __________.

Answer

Answer: noise pollution

11. The hearing range of human ears is __________.

Answer

Answer: 20 Hz to 20,000 Hz

12. The loudness of normal breathing of human is __________.

Answer

Answer: 10 dB

13. Vibration is a repeated __________ and __________ motion.

Answer

Answer: to, fro

14. The loudness of sound is determined by the __________ of vibration.

Answer

Answer: amplitude

15. The human voice box is called __________.

Answer

Answer: larynx

State whether the given statements are true or false.

1. All human beings can hear sounds of frequencies upto 60,000 Hz.

Answer

Answer: False

2. The sound in a sitar is produced by plucking its strings.

Answer

Answer: True

3. Sound cannot travel through vacuum.

Answer

Answer: True

4. Sound does not need a medium for its propagation.

Answer

Answer: False

5. The loudness is expressed in a unit called decibel.

Answer

Answer: True

6. Loud sounds have high frequencies.

Answer

Answer: False

7. Sound travel faster in air, slower in iron.

Answer

Answer: False

8. Light travels much faster than sound.

Answer

Answer: True

9. Man cannot hear sound of bats.

Answer

Answer: True

10. The time taken to complete one oscillation is called frequency.

Answer

Answer: False

11. Shriller sound has more frequency.

Answer

Answer: True

12. Tabla is a musical instrument.

Answer

Answer: True

13. The sound could not travel in solid.

Answer

Answer: False

14. The pitch of a sound depends in the frequency of the waves.

Answer

Answer: True

We hope the given NCERT MCQ Questions for Class 8 Science Chapter 13 Sound with Answers Pdf free download will help you. If you have any queries regarding Sound CBSE Class 8 Science MCQs Multiple Choice Questions with Answers, drop a comment below and we will get back to you soon.

Class 8 Science MCQ:

MCQ Questions for Class 9 Science Chapter 13 Why do we Fall Ill with Answers

Why do we Fall Ill Class 9 MCQ Online Test With Answers Questions

October 18, 2024

Check the below Online Education NCERT MCQ Questions for Class 9 Science Chapter 13 Why do we Fall Ill with Answers Pdf free download. MCQ Questions for Class 9 Science with Answers were prepared based on the latest exam pattern. We have Provided Why do we Fall Ill Class 9 Science MCQs Questions with Answers to help students understand the concept very well. https://ncertmcq.com/mcq-questions-for-class-9-science-with-answers/

You can refer to NCERT Solutions for Class 9 Science Chapter 13 Why do we Fall Ill to revise the concepts in the syllabus effectively and improve your chances of securing high marks in your board exams.

Class 9 Science Biology Chapter 13 MCQ With Answers

Biology Class 9 Chapter 13 MCQs On Why do we Fall Ill

Why Do We Fall Ill Class 9 MCQ Question 1.
Which one of the following is not a viral disease?
(a) Dengue
(b) AIDS
(c) Typhoid
(d) Influenza

Answer

Answer: (c) Typhoid

Why Do We Fall Ill MCQ Question 2.
Which one of the following is not a bacterial disease?
(a) Cholera
(b) Tuberculosis
(c) Anthrax
(d) Influenza

Answer

Answer: (d) Influenza

Class 9 Why Do We Fall Ill MCQ Question 3.
Which one of the following disease is not transmitted by mosquito?
(a) Brain fever
(b) Malaria
(c) Typhoid
(d) Dengue

Answer

Answer: (c) Typhoid

Class 9 Science Chapter 13 MCQ Question 4.
Which one of the following disease is not caused by bacteria?
(a) Typhoid
(b) Anthrax
(c) Tuberculosis
(d) Malaria

Answer

Answer: (d) Malaria

Class 9 Science Why Do We Fall Ill MCQ With Answers Question 5.
Which one of the following diseases is caused by protozoans?
(a) Malaria
(b) Influenza
(c) AIDS
(d) Cholera

Answer

Answer: (a) Malaria

Why Do We Fall Ill Class 9 MCQs Question 6.
Which one of the following has a long term effect on the health of an individual?
(a) Common cold
(b) Chicken pox
(c) Chewing tobacco
(d) Stress

Answer

Answer: (c) Chewing tobacco

Why Do We Fall Ill MCQ Questions With Answers Question 7.
Which of the following can make you ill if you come in contact with an infected person?
(a) High blood pressure
(b) Genetic abnormalities
(c) Sneezing
(d) Blood cancer

Answer

Answer: (c) Sneezing

Why Do We Fall Ill MCQs Question 8.
AIDS cannot be transmitted by
(a) sexual contact
(b) hugs
(c) breast feeding
(d) blood transfusion

Answer

Answer: (b) hugs

Why Do We Fall Ill MCQ Class 9 Question 9.
Making anti-viral drugs is more difficult than making anti-bacterial medicines because
(a) viruses make use of host machinery
(b) viruses are on the border line of living and non-living
(c) viruses have very few biochemical mechanisms of their own
(d) viruses have a protein coat

Answer

Answer: (c) viruses have very few biochemical mechanisms of their own

Class 9 Science Ch 13 MCQ Question 10.
Which one of the following causes kala-azar?
(a) Ascaris
(b) Trypanosoma
(c) Leishmania
(d) Bacteria

Answer

Answer: (c) Leishmania

MCQ On Why Do We Fall Ill Question 11.
If you live in a overcrowded and poorly ventilated house, it is possible that you may suffer from which of the following diseases:
(a) Cancer
(b) AIDS
(c) Air borne diseases
(d) Cholera

Answer

Answer: (c) Air borne diseases

Ch 13 Science Class 9 MCQ Question 12.
Which disease is not transmitted by mosquitoes?
(a) Dengue
(b) Malaria
(c) Brain fever or encephalitis
(d) Pneumonia

Answer

Answer: (d) Pneumonia

Class 9 Science Chapter 13 MCQ With Answers Question 13.
Which one of the following is not important for individual health?
(a) Living in clean space
(b) Good economic condition
(c) Social equality and harmony
(d) Living in a large and well furnished house

Answer

Answer: (d) Living in a large and well furnished house

Why Do We Fall Ill Class 9 MCQ Pdf Question 14.
Choose the wrong statement.
(a) High blood pressure is caused by excessive weight and lack of exercise.
(b) Cancers can be caused by genetic abnormalities.
(c) Peptic ulcers are caused by eating acidic food.
(d) Acne in not caused by staphylococci.

Answer

Answer: (c) Peptic ulcers are caused by eating acidic food.

MCQ Of Ch 13 Class 9 Science Question 15.
We should not allow mosquitoes to breed in our surroundings because they
(a) multiply very fast and cause pollution
(b) are vectors for many diseases
(c) bite and cause skin diseases
(d) are not important insects

Answer

Answer: (b) are vectors for many diseases

Question 16.
You are aware of Polio Eradication Programme in your city. Children are vaccinated because
(а) vaccination kills the polio causing microorganisms
(b) prevents the entry of polio causing organism
(c) it creates immunity in the body
(d) all the above

Answer

Answer: (c) it creates immunity in the body

Question 17.
Viruses, which cause hepatitis, are transmitted through
(a) air
(b) water
(c) food
(d) personal contact

Answer

Answer: (b) water

Question 18.
Vectors can be defined as
(a) animals carry the infecting agents from sick person to another healthy person
(b) microorganisms which cause many diseases
(c) infected person
(d) diseased plants

Answer

Answer: (a) animals carry the infecting agents from sick person to another healthy person

Fill in the blanks

1. Pneumonia is an example of ……………. disease.

Answer

Answer: Communicable

2. Many skin diseases are caused by ………………

Answer

Answer: Fungi

3. Antibiotics commonly block biochemical pathways important for the growth of ……………..

Answer

Answer: Bacteria

4. Living organisms carrying the infecting agents from one person to another are called …………….

Answer

Answer: Vector

5. …………… disease continues for many days and causes effect the on body.

Answer

Answer: Chronic, long-term

6. ……………. disease continues for a few days and causes short term effect on the body.

Answer

Answer: Acute

7. …………… is defined as physical, mental and social well-being and comfort.

Answer

Answer: Health

8. Common cold is an ……………. disease.

Answer

Answer: Infectious

9. Many skin diseases are caused by …………….

Answer

Answer: Fungi

Match the following columns

Column I	Column II
(a) Kala-azar	(i) Staphylococci
(b) Jaundice	(ii) Antibiotic
(c) Sleeping sickness	(iii) Female anopheles
(d) Acne	(iv) Sexually transmitted disease
(e) Virus	(v) Leishmania
(f) Vector	(vi) Trypanosoma
(g) Penicillin	(vii) Liver
(h) Plasmodium	(viii) SARS
(i) Syphilis	(ix) Malaria

Answer

Answer:

Column I	Column II
(a) Kala-azar	(v) Leishmania
(b) Jaundice	(vii) Liver
(c) Sleeping sickness	(vi) Trypanosoma
(d) Acne	(i) Staphylococci
(e) Virus	(viii) SARS
(f) Vector	(iii) Female anopheles
(g) Penicillin	(ii) Antibiotic
(h) Plasmodium	(ix) Malaria
(i) Syphilis	(iv) Sexually transmitted disease

We hope the given NCERT MCQ Questions for Class 9 Science Chapter 13 Why do we Fall Ill with Answers Pdf free download will help you. If you have any queries regarding Why do we Fall Ill CBSE Class 9 Science MCQs Multiple Choice Questions with Answers, drop a comment below and we will get back to you soon.

Class 9 Science Biology MCQ:

MCQ Questions for Class 9 Science Chapter 4 Structure of the Atom with Answers

Structure of the Atom Class 9 MCQ Online Test With Answers Questions

October 18, 2024

Check the below Online Education NCERT MCQ Questions for Class 9 Science Chapter 4 Structure of the Atom with Answers Pdf free download. MCQ Questions for Class 9 Science with Answers were prepared based on the latest exam pattern. We have Provided Structure of the Atom Class 9 Science MCQs Questions with Answers to help students understand the concept very well. https://ncertmcq.com/mcq-questions-for-class-9-science-with-answers/

You can refer to NCERT Solutions for Class 9 Science Chapter 4 Structure of the Atom to revise the concepts in the syllabus effectively and improve your chances of securing high marks in your board exams.

Class 9 Science Chemistry Chapter 4 MCQ With Answers

Chemistry Class 9 Chapter 4 MCQs On Structure of the Atom

Structure Of Atom Class 9 MCQ Question 1.
Which of the following correctly represents the electronic distribution in the Mg atom?
(a) 3, 8, 1
(b) 2, 8, 2
(c) 1, 8, 3
(d) 8, 2, 2

Answer

Answer: (b) 2, 8, 2

Structure Of Atom Class 9 MCQ With Answers Question 2.
Rutherford’s ‘alpha (α) particles scattering experiment’ resulted in the discovery of
(a) electron
(b) proton
(c) nucleus in the atom
(d) atomic mass

Answer

Answer: (c) nucleus in the atom

Class 9 Science Chapter 4 MCQ Question 3.
The number of electrons in an element X is 15 and the number of neutrons is 16. Which of the following is the correct representation of the element?
(a) \(_{15}^{31}\)X
(b) \(_{16}^{31}\)X
(c) \(_{15}^{16}\)X
(d) \(_{16}^{15}\)X

Answer

Answer: (a) \(_{15}^{31}\)X

MCQ On Structure Of Atom Class 9 Question 4.
Which of the following are true for an element?
(i) Atomic number = number of protons + number of electrons
(ii) Mass number = number of protons + number of neutrons
(iii) Atomic mass = number of protons = number of neutrons
(iv) Atomic number = number of protons = number of electrons
(a) (i) and (ii)
(b) (i) and (iii)
(c) (ii) and (iii)
(d) (ii) and (iv)

Answer

Answer: (d) (ii) and (iv)

Structure Of Atom MCQ Class 9 Question 5.
Atomic models have been improved over the years. Arrange the following atomic models in the order of their chronological order
(i) Rutherford’s atomic model
(ii) Thomson’s atomic model
(ii) Bohr’s atomic model
(a) (i), (ii) and (iii)
(b) (ii), (iii) and (i)
(c) (ii), (i) and (iii)
(d) (iii), (ii) and (i)

Answer

Answer: (c) (ii), (i) and (iii)

Class 9 Science Chapter 4 MCQ With Answers Question 6.
The ion of an element has 3 positive charges. Mass number of the atom is 27 and the number of neutrons is 14. What is the number of electrons in the ion?
(a) 13
(b) 10
(c) 14
(d) 16

Answer

Answer: (b) 10

Class 9 Science Ch 4 MCQ Question 7.
Identify the Mg²⁺ ion from the figure where, n and p represent the number of neutrons and protons respectively.

Answer

Answer: (d)

MCQ Structure Of Atom Class 9 Question 8.
The first model of an atom was given by
(a) N. Bohr
(b) E. Goldstein
(c) Rutherford
(d) J.J. Thomson

Answer

Answer: (d) J.J. Thomson

Structure Of The Atom Class 9 MCQ Question 9.
An atom with 3 protons and 4 neutrons will have a valency of
(a) 3
(b) 7
(c) 1
(d) 4

Answer

Answer: (c) 1

Class 9 Structure Of Atom MCQ Question 10.
Which of the following statement is always correct?
(a) An atom has equal number of electrons and protons.
(b) An atom has equal number of electrons and neutrons.
(c) An atom has equal number of protons and neutrons.
(d) An atom has equal number of electrons, protons and neutrons.

Answer

Answer: (a) An atom has equal number of electrons and protons.

MCQ On Structure Of Atom Class 9 Question 11.
Which of the following statements about Rutherford’s model of atom are correct?
(i) Considered the nucleus as positively charged.
(ii) Established that the a-particles are four times as heavy as a hydrogen atom.
(iii) Can be compared to solar system.
(iv) Was in agreement with Thomson’s model.
(a) (i) and (iii)
(b) (ii) and (iii)
(c) (i) and (iv)
(d) only (i)

Answer

Answer: (a) (i) and (iii)

MCQ Questions For Class 9 Science Chapter 4 Question 12.
Hydrogen exists in three isotopic forms, \(_{1}^{1}\)H, \(_{1}^{2}\)H, \(_{1}^{3}\)H known as protium, deuterium and tritium. Why are all the isotopes neutral in nature?
(a) Since neutrons are neutral in nature hence isotopes are electrically neutral.
(b) All the isotopes have one electron and one proton, hence they are neutral.
(c) All the isotopes have one proton and one neutron, hence they are neutral.
(d) Increasing number of protons in the isotopes make them neutral.

Answer

Answer: (b) All the isotopes have one electron and one proton, hence they are neutral.

Ch 4 Science Class 9 MCQ Question 13.
How many electrons are present in M-shell of an element with atomic number 20?
(a) 5
(b) 8
(c) 12
(d) 18

Answer

Answer: (b) 8

Chapter 4 Science Class 9 MCQ Question 14.
There are two atomic species X and Y, such that

Which of the following statements is true about X and Y?
(a) X and Y are isobars.
(b) X and Y have different chemical properties.
(c) X and Y have different physical properties.
(d) All of these.

Answer

Answer: (c) X and Y have different physical properties.

MCQ Of Structure Of Atom Class 9 Question 15.
The ion of an element has 3 positive charges. Mass number of the atom is 27 and the number of neutrons is 14. What is the number of electrons in the ion?
(a) 13
(b) 10
(c) 14
(d) 16

Answer

Answer: (b) 10

Question 16.
An alpha particle is also known as:
(a) subatomic particle
(b) an unionised helium atom
(c) a neutral particle
(d) a doubly-charged helium ion

Answer

Answer: (d) a doubly-charged helium ion

Question 17.
There are three isotopes of carbon which are named as C-12, C-13 and C-14 out of which C-12 is the most abundant isotope. In the given structures of 3 isotopes, what will be the composition of the nucleus?

(a) C-12 : 6p + 6n, C-13 : 7p + 6n, C-14 : 8p + 6n
(b) C-12 : 6p + 6n, C-13 : 6p + 7n, C-14 : 6p + 8n
(c) C-12 : 6p + 6n, C-13 : 5p + 8n, C-14 : 7p + 7n
(d) C-12 : 6p + 6n, C-13 : 12p + 1n, C-14 : 5p + 9n

Answer

Answer: (b) C-12 : 6p + 6n, C-13 : 6p + 7n, C-14 : 6p + 8n

Question 18.
The charge on an electron is equal to:
(a) 1.6 × 10^-19 C of -ve charge
(b) 2.6 × 10^-19 C of -ve charge
(c) 1.6 × 10^-22 C of -ve charge
(d) 1.6 × 10^-23 C of -ve charge

Answer

Answer: (a) 1.6 × 10^-19 C of -ve charge

Question 19.
Which of the following isotope is used in the treatment of blood cancer?
(a) P-32
(b) I-131
(c) Co-60
(d) any of these

Answer

Answer: (a) P-32

Question 20.
Isobars do not differ in the number of
(a) protons
(b) electrons
(c) neutrons
(d) nucleons

Answer

Answer: (d) nucleons

Fill in the blanks

1. Rutherford’s a-particle scattering experiment led to the discovery of the ……………….

Answer

Answer: atomic nucleus

2. Isotopes have same ……………… but different ……………..

Answer

Answer: atomic number, mass number

3. Neon and chlorine have atomic numbers 10 and 17 respectively. Their valencies will be ………….. and ……………. respectively.

Answer

Answer: 0 and 1

4. The electronic configuration of silicon is …………… and that of sulphur is ……………..

Answer

Answer: 2, 8, 4, and 2, 8, 6

5. Cathode rays consist of negatively charged particles known as ………………

Answer

Answer: electrons

6. ……………. are the atoms containing same number of neutrons.

Answer

Answer: isotones

7. The outermost shell of an atom is known as its ……………..

Answer

Answer: valence shell

8. Alpha particles are helium nuclei (He²⁺) and have …………. mass and ……………. units charge.

Answer

Answer: 4u and +2

9. The maximum number of electrons in a shell is given by ……………..

Answer

Answer: 2n²

10. Neutrons were discovered by …………….

Answer

Answer: James Chadwick

Match the names of the scientists given the columns A with their contributions towards the understanding of the atomic structure as given in column B.

Column A	Column B
(a) Ernest Rutherford	(i) Indivisibility of atoms
(b) J. J. Thomson	(ii) Stationary orbits
(c) Dalton	(iii) Concept of nucleus
(d) Neils Bohr	(iv) Discovery of electrons
(e) James Chadwick	(v) Atomic number
(f) E. Goldstein	(vi) Neutron
(g) Mosley	(vii) Canal rays

Answer

Answer:

Column A	Column B
(a) Ernest Rutherford	(iii) Concept of nucleus
(b) J. J. Thomson	(iv) Discovery of electrons
(c) Dalton	(i) Indivisibility of atoms
(d) Neils Bohr	(ii) Stationary orbits
(e) James Chadwick	(vi) Neutron
(f) E. Goldstein	(vii) Canal rays
(g) Mosley	(v) Atomic number

Column A	Column B
(a) Ions	(i) Same mass number, different atomic numbers.
(b) Isobars	(ii) Same number of neutrons, different mass numbers.
(c) Isotopes	(iii) Formed by loss or gain of electron
(d) Isotones	(iv) Combining capacity of an atom.
(e) Valency	(v) Same atomic numbers, different mass numbers.

Answer

Answer:

Column A	Column B
(a) Ions	(iii) Formed by loss or gain of electron
(b) Isobars	(i) Same mass number, different atomic numbers.
(c) Isotopes	(v) Same atomic numbers, different mass numbers.
(d) Isotones	(ii) Same number of neutrons, different mass numbers.
(e) Valency	(iv) Combining capacity of an atom.

Column A	Column B
Chlorine atom	2, 8
Sodium atom	2, 8, 7
Magnesium ion	2, 8, 2
Magnesium atom	2, 8, 1

Answer

Answer:

Column A	Column B
Chlorine atom	2, 8
Sodium atom	2, 8, 7
Magnesium ion	2, 8, 2
Magnesium atom	2, 8, 1

Answer the questions in one word:

1. Which symbols are used to represent different Bohr’s orbits?

Answer

Answer: K, L, M, N

2. Which isotope is used in the treatment of cancer?

Answer

Answer: Cobalt-60

3. What is the charge of anode rays?

Answer

Answer: positive

4. There are 14 protons and 13 neutrons in the nucleus of an atom. What is its mass number?

Answer

Answer: 27

5. Indicate the number of electrons, protons and neutrons in the element \(_{19}^{39}\)K.

Answer

Answer: e = 19, p = 19, n = 20

6. The atomic number of cation M²⁺ is 12. How many electrons are present in it?

Answer

Answer: 10

7. Which isotope of hydrogen is called protium?

Answer

Answer: \(_{1}^{1}\)H

8. Which particles determine the mass of an atom?

Answer

Answer: Protons, neutrons

Solve the crossword with the help of clues:

Across:
1. Part of atom responsible for mass.
3. Same mass number of species.
5. a-particle scattering experiment.
7. No. of valence electron in sodium.
Down:
2. Discovered the neutron.
4. Latest atomic model given by.
6. Negatively charged subatomic particle.
8. Positively charged substance particle.

Answer

Answer:

Across:
1. Nucleus
3. Isobar
5. Rutherford
7. One

Down:
2. Chadwick
4. Bohr
6. Electron
8. Proton

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MCQ Questions for Class 10 Science Chapter 3 Metals and Non-metals with Answers

Metals and Non-metals Class 10 MCQ Online Test With Answers Questions

October 18, 2024

Class 10 Science Chemistry Chapter 3 MCQ With Answers

Chemistry Class 10 Chapter 3 MCQs On Metals and Non-metals

Metals And Non Metals Class 10 MCQ Question 1.
Which of the following properties is generally not shown by metals?
(a) Electrical conduction
(b) Sonorous in nature
(c) Dullness
(d) Ductility
Answer:
(c) Dullness

Explanation: Metals generally do not show dullness. Metals such as gold and silver are usuaLly shiny rather than dull.

Related Theory:
Conduction: Metals are good conductors of heat and electricity as they have free electrons. Silver and copper are the best conductors of heat, whereas lead and mercury are poor conductors of heat. Sonorous: Metals that produces a sound on striking a hard surface.

Metallic lustre: Metal, in its pure state, has a shining surface. This property is known as metallic lustre. Ductility: The ability of metals to be drawn into thin wires. Cold is the most ductile metal.

Metal And Non Metals Class 10 MCQ Question 2.
The solution of one of the following compounds will not conduct electricity. This compound is:
(a) NaCl
(b) CCl₄
(c) MgCl₂
(d) CaCl₂
Answer:

Metals And Nonmetals Class 10 MCQ Question 3.
Which one of the following metals does not react with cold as well as hot water?
(a) Na
(b) Ca
(c) Mg
(d) Fe
Answer:

Class 10 Metals And Non Metals MCQ Question 4.
An aluminium strip is kept immersed in freshly prepared ferrous sulphate solution taken in a test tube, the change observed is that:
(a) Green solution slowly turns colourless
(b) Lower end of test tube becomes slightly warm
(c) A colourless gas with the smell of burning sulphur is observed
(d) Light green solution changes to blue
Answer:

Class 10 Science Chapter 3 MCQ Question 5.
Which of the following oxide(s) of iron would be obtained on the prolonged reaction of iron with steam?
(a) FeO
(b) Fe₂O₃
(c) Fe₃O₄
(d) Fe₂O₃ and Fe₃O₄
Answer:
(c) Fe₃O₄

Metals And Non Metals MCQ Question 6.
What happens when calcium is treated with water?
(I) It does not react with water.
(II) It reacts violently with water.
(III) It reacts Less violently with water.
(IV) Bubbles of hydrogen gas formed stick to the surface of calcium.
(a) (I) and (IV)
(b) (II) and (III)
(c) (I) and (II)
(d) (III) and (IV)
Answer:
(d) (III) and (IV)

Explanation: When calcium is treated with water, it reacts vigorously with water and to produce a cloudy white precipitate of calcium hydroxide and hydrogen gas is released as bubbles.

‘Related Theory
Sometimes hydrogen bubbles get stuck to the surface of calcium metaL making it tight arid thus calcium starts floating. Reaction of calcium with water is exothermic but the heat produced in this reaction is not sufficient so that hydrogen can catch

Ch 3 Science Class 10 MCQ Question 7.
Which of the foLLowing are not ionic compounds?
(I) KCl
(II) HCl
(III) CCl₄
(IV) NaCl
(a) (I) and (II)
(b) (II) and (III)
(c) (III) and (IV)
(d) (I) and (III)
Answer:

Class 10 Science Ch 3 MCQ Question 8.
Generally, non-metals are not Lustrous. Which of the following non-metals is lustrous?
(a) Sulphur
(b) Oxygen
(c) Nitrogen
(d) Iodine
Answer:
(d) Iodine

Explanation: Iodine is a non-metal with a lustrous appearance and exists in solid state.

Related Theory
Graphite is another non-metaL that is shiny and Lustrous.

MCQ On Metals And Non Metals Class 10 Question 9.
2 mt each of conc. HCL, HNO₃, and a mixture of conc. HCL and conc. HNO₃ in the ratio of 3:1 were taken in test tubes labelled as A, B and C. A small piece of metal was put in each test tube. No change occurred in test tubes A and B but the metaL got dissolved in test tube C. The metal could be:
(a) Al
(b) Au
(c) Cu
(d) Pt

Metal And Non Metals MCQ Class 10 Question 10.
An element A is soft and can be cut with a knife. This is very reactive to air and cannot be kept ¡n open air. It reacts vigorously with water. Identify the element from the following:
(a) Mg
(b) Na
(c) P
(d) Co
Answer:
(b) Na

Explanation: Na (sodium) possesses all the above properties. It is too soft and can be cut with a knife. It is also very reactive and reacts with oxygen or moisture present in air and produces sodium hydroxide, which is a highly exothermic reaction producing a lot of heat. It also reacts with water and burns due to the vigorous formation of hydrogen gas. That is why sodium is stored in kerosene oil to prevent any reaction.

MCQ On Metals And Non Metals Question 11.
Which among the following statements is incorrect for magnesium metal?
(a) It burns in oxygen with a dazzling white flame.
(b) It reacts with cold water to form magnesium oxide and evolves hydrogen gas.
(c) It reacts with hot water to form magnesium hydroxide and evolves hydrogen gas.
(d) It reacts with steam to form magnesium hydroxide and evoLves hydrogen gas.
Answer:

Metal And Non Metal Class 10 MCQ Question 12.
The electronic configurations of three elements X, Y and Z are X – 2, 8; Y – 2, 8, 7 and Z – 2, 8, 2. Which of the following ¡s correct?
(a) X is a metal
(b) Y is a metaL
(c) Z ¡s a non-metal
(d) Y is a non-metaL and Z is a metaL

MCQ Questions For Class 10 Science Chapter 3 Question 13.
In the given reaction,
Al₂O₃ + NaOH → X + H₂O.
What is element X?
(a) NaAlO₂
(b) Na₃Al
(c) Na₂O₃
(d) NaAl₂O₃ [Diksha]

MCQ Of Metal And Nonmetal Class 10 Question 14.
Sandhya took three beakers A, B and C containing zinc sulphate, silver sulphate and iron(ll) sulphate solutions respectively. Copper pieces were added to each beaker. The solution will appear blue in the case of:
(a) Beaker A
(b) Beaker B
(c) Beaker C
(d) Beakers B and C [Diksha]
Answer:
(b) Beaker B

Explanation: The solution will appear blue in Beaker B. Let us see how.

When pieces of copper metal are kept immersed in silver sulphate solution for some time, the solution gradually becomes blue and a shiny greyish-white deposit of silver metal is formed on the copper strip.

In this reaction, copper metal is displacing silver from silver sulphate solution, forming copper sulphate and silver metal. The solution becomes blue due to the formation of copper sulphate. The reason behind this displacement reaction is that copper is more reactive than silver.

On the other hand, copper metal is less reactive than iron and zinc and hence cannot displace them from their respective salt solutions.

Chapter 3 Science Class 10 MCQ Question 15.
Arrange the following metal in the decreasing chemical activity series.
(I) Potassium
(II) Magnesium
(III) Gold
(IV) Iron
Correct options are:
(a) (I), (II), (III) and (IV)
(b) (I), (III), (IV) and (II)
(c) (I), (II), (IV) and (III)
(d) (I), (IV), (II) and (III)

Question 16.
Which metal can be displaced by copper from Its salt solution?
(I) Silver
(II) Magnesium
(III) iron
(IV) Iron
Correct options are:
(a) (I) and (II)
(b) (I) and (III)
(c) (II) and (III)
(d) (I) and (IV)
Answer:
(d) (I) and (IV)

Silver and mercury are less reactive than copper and as copper will displace those metals from its salt solution which are less reactive than it, the correct option is (d).

Question 17.
Metals are refined by using different methods. Which of the following metals are refined by electrolytic refining?
(I) Au
(II) Cu
(III) Na
(IV) K
(a) (I) and (II)
(b) (IV) and (III)
(c) (II) and (III)
(d) (II) and (IV)
Answer:
(a) (I) and (II)

Explanation: Gold (Ag) and copper (Cu) obtained after extraction are in impure form. So, metals Au (gold) and Cu (copper) are refined by electrolytic refining. Other than gold and copper, electrolytic refining is used for metals such as Zn and Ag. Sodium (Na) and potassium (K) are extracted by electrolytic reduction. Metals obtained after electrolytic reduction are in pure form.

Related Theory
Alkali metals are very reactive, so they cannot be refined with the help of the electrolytic refining process.

Question 18.
Galvanisation is a method of protecting iron from rusting by coating it with a thin layer of:
(a) Gallium
(b) Aluminium
(c) Zinc
(d) Silver
Answer:
(c) Zinc

Explanation: Zinc (Zn) metal is used to protect iron surfaces from rusting.

Related Theory
Galvanization is basically coating iron or steel with a layer of zinc to prevent it from rusting. Water pipes are also galvanized to prevent corrosion.

Question 19.
Stainless steel is a very useful material in our life, in stainless steel, iron is mixed with:
(a) Mi and Cr
(b) Cu and Cr
(c) Mi and Cu
(d) Cu and Au
Answer:
(a) Ni and Cr

Explanation: Stainless steel is an alloy of iron (74%), nickel (8%) and chromium (18%).

Related Theory
‘Alloying elements enhance the structure and properties such as durability, strength and toughness of the metal. It makes them corrosion-resistant.

Question 20.
If copper is kept in the open air, it slowly loses its shining brown surface and gains a green coating. It is due to the formation of:
(a) CuSO₄
(b) CuCO₃
(c) CU(NO₃)₂
(d) CuO
Answer:

Question 21.
Which of the following metals are obtained by electrolysis of their chlorides in a molten state?
(I) Na
(II) Ca
(III) Fe
(IV) Cu
(a) (I)and(IV)
(b) (III) and (IV)
(c) (I) and (III)
(d) (I) and (II)
Answer:

Question 22.
An electrolytic cell consists of:
(I) Positively charged cathode
(II) Negatively charged anode
(III) Positively charged anode
(IV) Negatively charged cathode
(a) (I) and (II)
(b) (III) and (IV)
(c) (I) and (III)
(d) (II) and (IV)
Answer:
(b) (III) and (IV)

Explanation: There is a positively charged anode and a negatively charged cathode in an electrolytic cell. Positively charged ions (cations) are deposited at the negatively charged cathode. Negatively charged ions (anions) are deposited at the positively charged anode.

Question 23.
During electrolytic refining of zinc, it gets:
(a) Deposited on the cathode
(b) Deposited on the anode
(c) Deposited on the cathode as well as anode
(d) Remains in the solution
Answer:

Question 24.
Alloys are homogeneous mixtures of a metal with a metal or non-metal. Which among the following alloys contains non-metal as one of its constituents?
(a) Brass
(b) Bronze
(c) Amalgam
(d) Steel
Answer:
(d) Steel

Explanation: SteeL contains non-metal as one of its constituents. Steel is an alloy made by combining iron and other elements, mainly carbon. Carbon gives strength to iron. It is used to make buildings, ships, automobiles, machines, and appliances.

Related Theory

Brass – Copper and zinc
Bronze – Copper and tin
Amalgam – Mercury with other metal
Steel – Iron with carbon

Question 25.
Which among the following alloys contains mercury as one of its constituents?
(a) Stainless steel
(b) Alnico
(c) Solder
(d) Zinc amalgam
Answer:

Question 26.
Which one of the following figures correctly describes the process of electrolytic refining?

Answer:

Explanation: In the electrolytic refining process, impure metal forms the anode, which is the positive electrode, whereas pure metal forms the cathode which is the negative electrode.

Figure (c) shows the process of electrolytic refining of copper metal. Copper from impure anode dissolves into the solution. Copper ions (Cu²⁺) from the solution are deposited on the cathode and impurities settle down below the anode as anode mud.

Question 27.
Select the incorrect statements):
(I) Solder is an alloy of lead and copper
(II) Solder is an alloy of lead and tin
(III) Melting point of solder is low
(IV) Melting point of solder is high
(a) Only (I)
(b) Both (I) and (III)
(c) Both (II) and (IV)
(d) Both (I) and (IV)
Answer:

Question 28.
All ionic compounds:
(a) Have high melting point but the low boiling point
(b) Are generally soluble in kerosene
(c) Are generally brittle
(d) Conduct electricity in solid-state
Answer:

Question 29.
The cations and anions present in aluminium oxide are:

Answer:
(b) Cation: Al³⁷; Anion: O^2-

Explanation: Aluminium oxide or Al₂O₃ is formed by the transfer of electrons from aluminium atoms to oxygen atoms.

Aluminium (Atomic number = 13) has 3 valence electrons whereas oxygen (atomic number = 8) has 2 valence electrons.

So, each aluminium atom donates its 3 valence electrons to the oxygen atoms and forms cations [Al³⁺], whereas each oxygen atom gains two electrons and forms anions [O^2-].

Question 30.
The metals which have very low melting points are:
(a) Gallium and caesium
(b) Gallium and sodium
(c) Caesium and potassium
(d) Sodium and potassium

Assertion Reasoning questions Class 10 Science Chapter 3

For the following questions, two statements are given – one labelled Assertion (A) and other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below:
(a) Both (A) and (R) are true and (R) is the correct explanation of the assertion.
(b) Both (A) and (R) are true, but (R) is not the correct explanation of the assertion.
(c) (A) is true, but (R) is false.
(d) (A) is false, but (R) is true.

Question 31.
Assertion (A): Alkali metals like sodium and potassium can be cut with a knife.
Reason (R): They have high densities.
Answer:
(c) (A) is true but (R) is false.

Explanation: Alkali metals like sodium and potassium are so soft that they can be cut with a knife as they have low densities.

Question 32.
Assertion (A): Magnesium is less reactive than sodium.
Reason (R): Sodium reacts more vigorously with oxygen than magnesium.
Answer:

Question 33.
Assertion (A): In the following reaction between calcium and water, calcium starts floating.
Ca + 2H₂O → Ca(OH)₂ + H₂
Reason (R): Calcium hydroxide is lighter than water.
Answer:
(c) (A) is true but (R) is false.

Explanation: In the reaction between calcium and water, calcium starts floating because the bubbles of hydrogen gas formed stick to the surface of calcium metal.

Question 34.
Assertion (A): Hydrogen gas is evolved when a metal reacts with nitric acid.
Reason (R): Nitric acid is a strong oxidizing agent.
Answer:

Question 35.
Assertion (A): The compound MgCl₂ will not conduct electricity in a solid-state.
Reason (R): Movement of ions in ionic compounds is not possible in solid-state.
Answer:
(b) Both (A) and (R) are. true but (R) is not the correct explanation of the (A).

Explanation; The compound MgCl₂ is an ionic compound as it is formed by the transfer of electrons between magnesium and chlorine. It will not conduct electricity in solid-state as the movement of ions in ionic compounds is not possible in a solid-state.

Question 36.
Assertion (A): The metals and alloys are good conductors of electricity.
Reason (R): Bronze Is an alloy of copper and tin and it is not a good conductor of electricity.
Answer:
(d) (A) is false but (R) is true.

Explanation: All the metals and alloys are not always good conductors of electricity like bronze is not a good conductor of electricity, its constituents are copper and tin. Copper is a good conductor whereas tin is not a good conductor of electricity. Alloy nichrome is a good conductor of electricity.

Related Theory

Metals are good conductors of electricity because they.
have a large number of free electrons.
Possess small resistivity in the range of 10-8 W m to 10-6 W m. Whereas alloys have more resistivity.

(Competency Based Questions (CBQs))

Question 1.
The exact date that humans first began to mine gold is unknown, but some of the oldest known gold artefacts were found in the Varna Necropolis in Bulgaria. The graves of the necropolis were built between 4700 and 4200 BC, indicating that gold mining could be at least 7000 gears old. In the area of the Kolar Gold Fields in Bangarpet Taluk, Kolar District of Karnataka state, India, gold was first mined prior to the 2nd and 3rd century AD by digging small pits. (Golden objects found in Harappa and Mohenjo-daro have been traced to Kolar through the analysis of impurities — the impurities include 11% silver concentration, found only in KGF ore.

In nature, aluminium is found in a combined state whereas silver/gold is found in Freestate. Give reason.
Answer:
Silver and gold are least reactive metals and are often found in their native or free state. Aluminium is a very reactive metal and is never found in free state, but in combined state.

Question 2.
Dhanteras, also known as Dhanatrayodashi, is the first day that marks the festival of Diwali in India. Dhanteras is the worship of lord Dhanvantari. Fundus considers this an extremely auspicious day for making new purchases, especially of gold or silver articles and new utensils. It is believed that new “Dhan” (wealth} or some item made of precious metal is a sign of good. luck. In modern times, Dhanteras has come to be known as the most: auspicious occasion for buying gold, silver, and other metals, especially kitchenware. Palak, along with her mother, purchased some kitchenware articles made of stainless steel on this occasion.

How does alloying of iron change its properties?
Answer:
Pure iron is very soft arid stretches easily when hot but if iron ismixed with a small amount of carbon (about 0.05 %), it becomes hardand strong. When iron is mixed with nickel and chromium, we getstainless steel, which is hard and does not rust. Thus, if iron is mixedwith some other substance, its properties change.

Question 3.
Have you ever imagined what would happen if all the electrical wires used in our homes, offices and other places were without any covering? Well, people handling them would die of electrical chock and there would be short-circuiting leading to electrical fires all around us!

Electrical wires have a coating of an insulating material. The material, generally used is:
(a) Sulphur
(b) Graphite
(c) PVC
(d) All can be used
Answer:
(c) PVC

Explanation: An insulating substance is required to coat the electrical wire such as PVC, PVC is a polymer and a bad conductor of electricity, it is the most common insulating material used to insulate electrical conductors from electric charge, thus preventing direct human contact with electricity.

Graphite is a good conductor of electricity. Hence, it cannot be used as insulating material. Sulphur, although a bad conductor of electricity, is brittle in nature. So, it cannot be used as an insulating material.

Question 4.
Analyse the following reactivity series given below and answer the questions that follow:

(A) Which of the two metals is more reactive: copper or silver?
Answer:

(B) What will happen if a strip of zinc is immersed in o solution of copper sulphate?
Answer:
When a strip of zinc metal is put in copper sulphate solution, then the blue colour of copper sulphate solution fades gradually and red-brown coating of copper is deposited on zinc strip.

This is an example of displacement reaction.

Explanation: Zinc is more reactive than copper so it will displace copper from its salt solution so displacement reaction takes place.

(C) If copper is kept open in air, it slowly Loses its shining brown surface and gains a green coating. It is due to the formation
(a) Acidic CuSO₄
(b) Basic CuCO₃
(c) Acidic Cu(NO₃)₂
(d) Basic CuO
Answer:

(D) Which one of the following four metals would be displaced from the soLution of its softs by other three metals?
(a) Mg
(b) Ag
(c) Zn
(d) Cu
Answer:
(b) Ag

Explanation: Least reactive metal can be displaced from its solution by other three metals. Silver is least reactive out of the given four metals.

Related Theory
Basic copper carbonate is an undesired layer formed on the surface of the copper and the process is known as corrosion.

Question 5.
Aqua regia is a yellow-orange (sometimes red) fuming liquid, so named by alchemists because it can dissolve the noble metals gold and platinum, though not all metals.

The composition of aqua-regia is:

Answer:

Explanation: Aqua-regia is a mixture of concentrated hydrochloric acid and concen¬trated nitric acid in the ratio of 3:1. Aqua-regia, being a strong acid, dissolves gold.

Question 6.
Atoms that gain electrons and therefore have a net negative charge are known as anions. Conversely, atoms that lose electrons and therefore have a net positive charge are called cations. Cations tend to be metals, while anions tend to be non-metals. Ions may also be single atoms or multiple, complex groups of atoms. When we talk about ions, it’s true that opposites attract.

The opposite negative and positive charges of the ions hold together in ionic bonds, forming ionic compounds, which are just what they sound like: compounds made of ions. The loss or gain from one atom matches the loss or gain of the other, so one atom essentially ‘donates’ an electron to the other atom it pairs up with. Two positive or two negative ions will not join together because they have the same charge. But one positive and one negative will happily join together to make an ionic compound.
(A) Explain the formation of MgO. (Atomic No. of O = 8, Mg = 12).
Answer:
Electronic configuration of Mg: 2, 8, 2 and that of O: 2, 6.
Magnesium atom loses its two valence electrons to form Mg²⁺ ion and oxygen atom gains two electrons to form O₂ ion thereby achieving their nearest inert gas configuration.

(B) Will the aqueous solution of MgO conduct electricity? If yes, give reasons for your answer?
Answer:

(C) Name a solvent in which ionic compounds are soluble and a solvent in which they are insoluble.
Answer:
Ionic compounds are soluble in water and insoluble in kerosene.

(D) Why do ionic compounds have high melting and boiling points?
Answer:

Question 7.
When Rohan was suffering from fever, the doctor had asked his parents to check his temperature every 2 hours and also to keep a record. He was a thermometer that has a certain metal in a liquid state inside it

Generally, metals are soLid in nature. Which one of the following metals is found in Liquid state at room temperature?
(a) Na
(b) Fe
(c) Cr
(d) Hg
Answer:
(d) Hg

Explanation: At room temperature, mercury (Hg) is the only metal found in a liquid state.

Related Theory
All other metals are solid at room temperature. Hg also has the lowest melting point.

Question 8.
Collect the samples of the following metals aluminium, copper, iron, lead, magnesium, zinc and sodium. Hold each of the samples above with a pair of tongs and try burning over a flame. It would be better if students wear eye protection and perform this activity with assistance from the teacher. Repeat with the other metal samples.
(A) Select the incorrect statements).
(I) All metals burn easily.
(II) Not all metals burn easily.
(III) Magnesium burns easily.
(IV) Copper and aluminium take time to burn.
(a) Only (I)
(b) Only (II)
(c) Both (I) and (III)
(d) Both (II) and (IV)
Answer:

(B) The student performing this activity noted the following observations on the colour of flame observed when the metal is burnt.

Select the correct observation.
Answer:
(d) Metal: Magnesium; Colour of Flame: White

Explanation: The colour of flame observed when the given metals are heated is given below:
Aluminium: Silvery white
Copper: Blue
Sodium: Yellow
Magnesium: White

(C) The correct arrangement of metaLs Al, Mg, Na and Zn in the decreasing order of their reactivity towards oxygen ¡s:
(a) Na > Al > Mg > Zn
(b) Na > Mg > Al> Zn
(c) Na > Al > Zn > Mg
(d) Mg > Na > Al > Zn
Answer:
(b) Na > Mg > Al > Zn

Explanation: Almost all metals combine with oxygen to form metal oxide. However, the reactivities of different metals towards oxygen are different. The most reactive of the given metals is Na followed by Mg, Al and Zn.

(D) Which of the following metal oxides are soluble in water?
(I) CuO
(II) Na20
(III) FeO
(IV) K20
(a) Both (I) and (II)
(b) Both (I) and (III)
(c) Both (II) and (IV)
(d) Both (I) and (IV)
Answer:
(c) Both (II) and (IV)

Explanation: Most metal oxides are
insoluble in water but some of these dissolve in water to form alkalis. Sodium oxide and potassium oxide dissolve in water to produce alkalis as follows:
Na₂O(s) + H₂O(l) → 2NaOH(aq)
K₂O(s) + H₂O(l) → 2KOH(aq)

(E) Metals such as sodium and potassium are kept immersed in:
(a) Kerosene oil
(b) Water
(c) Carbon disulphide
(d) Alcohol
Answer:

Question 9.
Pritha’s mother had lots of silver jewellery which she had kept in a jewellery box. One day, when she took them out to show them to her friends, she was surprised to see that most of them had a black coating over them.

Silver articles become black on prolonged exposure to air. This is due to the formation of:
(a) Ag₃N
(b) Ag₃O
(c) Ag₂S
(d) Ag₃S and Ag₃N
Answer:
(c) Ag₂S

Explanation: Silver metal reacts with atmos¬pheric sulphur compounds like H₂S gas and forms a black coating of Ag₂S over the surface. This reaction is as below:

Question 10.
Take samples of sodium chloride, potassium iodide, barium chloride or any other salt from the science laboratory. Take a small amount of a sample on a metal spatula and heat directly on the flame as shown in fig. Also try to dissolve the samples in water, petrol and kerosene.

Heating a sail sample on a spatula

Make a circuit as shown in Fig. and insert the electrodes into a solution of one salt.

(A) The physical state and properties of the salt samples used in the activity is:
(I) All are crystalline solids
(II) All are brittle
(III) Not all are hard
(IV) Not all are brittle
Which of the statements above is correct?
(a) Both (I) and (III)
(b) Both (I) and (II)
(c) Both (II) and (III)
(d) Both (III) and (IV)
Answer:
(b) Both (I) and (II)

Explanation: All the salts are ionic compounds and are crystalline solids and hard due to the strong force of attraction between the positive arid negative ions. They are also brittle.

(B) Select the correct, observation when the salt sample is taken on a metal spatula and heated directly on the flame:
(a) The salts melt immediately
(b) The salts give out characteristics flame upon heating
(c) The salts do not melt easily
(d) The salts undergo sublimation
Answer:
(c) The salts do not melt easily

Explanation: The given salts are ionic compounds that have very high melting and boiling points as a large amount of energy is required to break the strong inter-ionic attraction.

(C) The solution of which of the following compounds will not conduct electricity?
(a) CCl₄
(b) NaCl
(c) CaCl₂
(d) KBr
Answer:

(D) A student noted the following observations with four compounds A, B, C and D.

Which of the compounds A, B, C and D are ionic compounds?
(a) A and B
(b) B and C
(c) C and D
(d) A and D
Answer:

(E) Select the correct statement regarding the electrical conductivity of ionic compounds:
(a) The salt samples in the activity conduct electricity in their solid-state.
(b) The salt samples in the activity conduct electricity in a solution of water.
(c) The salt samples do not conduct electricity in a molten state.
(d) The salt samples do not conduct electricity in solution or in molten state.
Answer:

Question 11.
Displacement reactions are very important reactions of chemistry. They have many applications in various fields some of which are listed below:
(1) It is used in thermite welding.
(2) It is used in making alloy steel.
(3) It is used in the extraction of various metals.
(4) It is used in treating acid indigestion.
A thermite reaction is a single displacement reaction between iron oxide and aluminium which is also a highly exothermic reaction. The extreme heat released from this reaction is sufficient to melt the iron product.

(A) The correct chemical equation describing the thermite process is:
(a) Fe₂O₃(s) + 2Al(s) + Heat → 2Fe(s) + Al₂O₃(l)
(b) Fe₂O₃(s) + 2Al(S) → 2Fe(l) + Al₂O₃(s) + Heat
(c) 3FeO(s) + 2Al(S) + Heat → 3Fe(l) + Al₂O₃(s)
(d) 3FeO(s) + 2Ai(s) → 3Fe(l) + Al₂O₃(s) + Heat
Answer:
(b) Fe₂O₃(s) + 2Al(s) → 2Fe(l) + Al₂O₃(s) + Heat

Explanation: Thermite reaction is the reaction between iron (III) oxide or Fe₂O₃ and aluminium. It is a highly exothermic process (shown by “+ Heat” in the product side) and iron is produced in the molten state. It is used to join is used tojoin railway tracks or cracked machine parts.

(B) What happens when zinc metal is added to G test tube containing Al₂(SO₄)₃ solution?
(a) Zinc displaces aluminium from its salt solution
(b) No reaction takes place
(c) The solution becomes blue in colour
(d) The solution becomes colourless and aluminium metal is deposited.
Answer:
(b) No reaction takes place

Explanation: No reaction takes place as zinc is less reactive than aluminium and cannot displace aluminium from its salt solution, namely, Al₂(SO₄)₃ solution.

(C) A student made the following observations after studying the following displacement reactions between a metal and a salt solution of a different metal:
(i) Mg + ZnSO₄ → MgSO₄ + Zn
(ii) Zn + CuSO₄ → ZnSO₄ + Cu
(iii) Co + MgSO₄ → CaSO₄ + Mg
Selsect the incorrect observation(s):
(i) Calcium will displace copper from copper sulphate solution.
(II) Magnesium will be displaced by both calcium and zinc
(II) The least reactive metal out of Mg, Ca, Cu and Zn are Zinc.
(IV) The most reactive metal out of Mg, Ca, Cu and Zn is calcium.
(a) Both (I) and (II)
(b) Both (I) and (III)
(c) Both (II) and (III)
(d) Both (I) and (IV)
Answer:

(D) An activity was performed by a student to find the reactivity of four metals- A, B, C and D by taking salt solutions of four metals in four test tubes numbered 1 to 4 and adding the samples of each metal one by one to each of the test tubes.

The observations recorded by the student are as given below:

The correct arrangement of the given metals A, B, C and D in decreasing order of their reactivities is:
(a) C < B < A < D
(b) B < C < A < D
(c) C < B < D < A
(d)D < A < B < C
Answer:

(E) A student performed an experiment to study the displacement reaction of metals. He took two test tubes X and Y containing copper sulphate and silver nitrate solutions respectively.

He dipped a strip of zinc in test tube X and copper strip in test tube Y and recorded his observations as shown below. Select the correct observation:

Answer:
(d) Test Tube X: Reaction takes place; Test Tube Y: Reaction takes place.

Explanation: Zinc is more reactive than copper and will displace copper from copper (II) sulphate solution in test tube X.
Zn + CuSO₄ → ZnSO₄ + Cu
Also, copper is more reactive than silver and will displace silver from silver nitrate solution in test tube Y.
Cu + 2AgNO₃ → Cu(NO₃)₂ + 2Ag

Question 12.
A fusible metal alloy is used to create a permanent bond between metal workpieces. The alloy is melted in order to adhere to and connect the pieces after cooling, which requires that the alloy have a lower melting point than the pieces being joined. The alloy should also be resistant to oxidative and corrosive effects that would degrade the joint over time.

Name an alloy that is used for welding electrical wires together and also give its composition.
Answer:
Solder is an alloy that is used for welding electrical wires together. It is an alloy of lead and tin (Pb and Sn) and has a low melting point.

Question 13.
Sam went to the grocery store with his mother one day.
He observed that pickles, curds and other sour things are always stored in glass or plastic containers and never in any container made of a metal or alloy. He later found out that this is related to the chemical properties of metals as metals react with acids.

(A) Metals react with dilute acids to give:
(a) Salt and water
(b) Salt and hydrogen gas
(c) Salt and carbon dioxide gas
(d) Salt, water and carbon dioxide gas
Answer:
(b) Salt and hydrogen gas

Explanation: Most metals react with dilute acid to give the metal salt and hydrogen gas. Example:
Zn(s) + H₂SO₄ (aq) → ZnSO₄(aq)) + H₂(g)

(B) Which of the following metal will react with dilute hydrochloric acid?
(I) Cu
(II) Zn
(III) Al
(IV) Ag
(a) Only (I)
(b) Only (II)
(c) Both (I) and (IV)
(d) Both (II) and (III)
Answer:

(D) Some students reacted an insoluble metal oxide with a dilute acid to form a soluble salt with a characteristic blue colour.
The insoluble metal oxide and the soluble salt could be:

Answer:

(E) The correct arrangement of metals Mg, Zn, Fe and Al in decreasing order of their reactivity with dilute acids is:
(a) Al > Mg > Zn > Fe
(b) Al > Mg > Fe > Zn
(c) Mg > Al > Zn > Fe
(d) Mg > Al > Fe > Zn
Answer:
(c) Mg > Al > Zn > Fe

Explanation: Out of the metals Mg, Zn, Fe and Al, Mg will react most vigorously with dilute acid, followed by Al, Zn and Fe.

Question 14.
While walking along the roadside with his grandfather, Aman observed that many iron pipes had developed cracks on their surfaces.

(A) Metals react with dilute acids to give:
(a) Salt and water
(b) Salt and hydrogen gas
(c) SaLt ared carbon dioxide gas
(d) Salt, water and carbon dioxide gas
Answer:
(b) Salt and hydrogen gas
Explanation: Most metals react with dilute acid to give the metal salt and hydrogen gas.
Example:
Zn(s) + H₂SO₄ (aq) → ZnSO₄(aq) + H₂(g)

(B) Which of the following metal will react with dilute hydrochloric acid?
(I)Cu
(II)Zn
(III)AL
(IV)Ag
(a) Only (I)
(b) Only (II)
(c) Both (I) and (IV)
(d) Both (il) and (III)
Answer:

(D) Some students reacted an insoluble metal oxide with a dilute acid to form a soluble salt with a characteristic blue colour.
The insoluble metal oxide and the soluble salt couLd be:

(E) The correct arrangement of metals Mg, Zn, Fe and AL in decreasing order of their reactivity with diLute acids is:
(a) Al > Mg > Zn> Fe
(b) Al > Mg> Fe > Zn
(c) Mg > Al> Zn > Fe
(d) Mg > Al > Fe > Zn
Answer:
(c)Mg > Al > Zn > Fe
Explanation: Out of the metals Mg, Zn, Fe and Al, Mg will react most vigorously with dilute acid, folLowed by At. Zn and Fe.

Question 15.
While walking along the roadside with his grandfather, Aman observed that many iron pipes had developed cracks on their surfaces.

Being inquisitive in nature and atso having Learned about the phenomenon of corrosion, Aman searched the internet for more information about corrosion and its prevention and found out that the most important factor in atmospheric corrosion, overriding pollution or lack of it, is moisture, either in the form of rain, dew, condensation, or high relative humidity (RH). In the absence of moisture, most contaminants would have little or no corrosive effect.

(A) Identify the correct statement:
(a) Rusting of iron is caused only by water.
(b) Rusting of iron is caused only by air,
(c) Rusting of iron is caused only by impurities.
(d) Rusting of iron is caused by both air and water.
Answer:

(B) Two students noted down the following observations after studying the graph showing the effect of reLative humidity on the rate of corrosion in iron

Select the correct option.
(C) Chemically rust is:
(a) Hydrated Iron (II) oxide
(b) Hydrated Iron (III) oxide
(c) Iron (III) sulphate
(d) Iron (III) oxide
Answer:
(c) Student A: Rate of corrosion is high for neiative humidity between 50% – 60%; Student B: Rate of corrosion… >60%.

Explanation: From the graph, we observe that the rate of corrosion depends upon the relative humidity and it increases with increase in the relative humidity.

Rate of corrosion is minimal for relative humidity < 40 %, is low for relative humidity between 40 % to 50 %. is high for relative humidity between 50% – 60 % and is extreme for relative humidity > 60 %.

(D) Which of the following statement is /are incorrect about corrosion?
(I) The black coating on silver articles is due to formation of basic silver oxide when silver reacts with oxygen present in air.
(II) The green coating on copper articles is due to formation of copper carbonate.
(III) The brown flaky substance formed on iron articles is due to the formation of rust.
(IV) The black coating on silver articles is due to formation of silver sulphide when silver reacts with hydrogen sulphide present in air.
(a) Only (I)
(b) Only (II)
(c) Both (I) and (III)
(d) Both (II) and (IV)
Answer:
(a) Only (I)

(E) 0 Rusting of iron can be prevented by :
(a) Galvanisation only
(b) Alloying only
(c) Both (a) and (b)
(d) Neither (a) nor (b)
Answer:

Very Short Answer Type Questions

Question 1.
A metal combines with a non-metal to form a compound Y. Will it dissolve in an organic solvent or not?
Answer:
Metals combine with non-metals to form ionic compounds by transfer of electrons. Ionic compounds do not dissolve in organic solvents but are soluble in water.

Question 2.
An element E combines with 02 to form an oxide E20, which is a good conductor of electricity. Write the formula of the compound formed when it combines with chlorine?
Answer:

Question 3.
Why do ionic compounds conduct electricity in molten state?
Answer:
ionic compounds conduct electricity in molten state because the ions move freely in molten state since the electrostatic force of attraction between oppositely charged ions is overcome due to heat.

Question 4.
Why should the metal sulphides and carbonates be converted to metal oxides in the process of extraction of metal from them?
Answer:
Usually, metal sulphides and carbonates are converted to metal oxides in the process of extraction of metal. This is because extraction of a metal from its oxide is easier as compared to its extraction from its sulphides and carbonates. Metal oxides can easily reduce to metal with the help of a common reducing agent like coke.

Question 5.
From amongst the metal, sodium, calcium, aluminium, copper and magnesium, name the metal:
(A) Which reacts with water only on boiling.
(B) Another one which does not. react even with steam.
Answer:
(A) The metal which reacts with water only on boiling is magnesium as it does not react with cold water.
(B) The metal which does not react even with steam is copper.

Question 6.
An element ‘A’ form two oxides AO and AO₂. The oxide AO is neutral whereas the oxide AO₂ is acidic in nature. Would you call element ‘A’ a metal or a non-metal?
Answer:

MCQ Questions for Class 10 Science with Answers

Class 10 Science Chemistry MCQ:

MCQ Questions for Class 10 Science Chapter 5 Periodic Classification of Elements with Answers

Periodic Classification of Elements Class 10 MCQ Online Test With Answers Questions

October 18, 2024

Class 10 Science Chemistry Chapter 5 MCQ With Answers

Chemistry Class 10 Chapter 5 MCQs On Periodic Classification of Elements

Periodic Classification Of Elements Class 10 MCQ Question 1.
Which of the following statements) about the modern periodic table are incorrect?
(I) The elements in the modern periodic table are arranged on the basis of their decreasing atomic numbers.
(II) The elements in the modern periodic table are arranged on the basis of their increasing atomic masses.
(III) Isotopes are placed in adjoining group(s) in the periodic table.
(IV) The elements in the modern periodic table are arranged on the basis of their increasing atomic number.
(a) Only (I)
(b) (I), (II), and (III)
(c) (I), (II), and (IV)
(d) Only (IV)
Answer:
(b) (I), (II), and (III)

Explanation: The modern periodic table is a tabular arrangement of elements in increasing order of their atomic number, which is why isotopes are placed at the same position. Hence, only (III) is correct.

Periodic Table Class 10 Icse MCQ Question 2.
Which of the following statements about the modern periodic table is correct?
(a) It has 18 horizontal rows known as periods.
(b) It has 7 vertical columns rows known as periods.
(c) It has 18 vertical columns known as groups.
(d) It has 7 horizontal rows known as groups.
Answer:

MCQ On Periodic Classification Of Elements Question 3.
An element X is forming the acidic oxide. Its most probable position in the modern periodic table is:
(a) Group 1 and Period 3
(b) Group 16 and Period 3
(c) Group 17 and Period 3
(d) Group 2 and Period 3
Answer:

Class 10 Science Chapter 5 MCQ Question 4.
Which of the given elements A, B, C, D and E with atomic numbers 2, 3, 7,10 and 30 respectively belong to the same period?
(a) A, B, C
(b) B, C, D
(c) A, D, E
(d) B, D, E
Answer:

MCQ On Periodic Classification Of Elements Class 10 Pdf With Answers Question 5.
On the basis of the electronic configuration of x|, the group number and period of the element ‘X is:
(a) Group 15 period 2
(b) Group 13 period 2
(c) Group 9 period 5
(d) Group 13 period 5
Answer:
(b) Group 13 period 2

Explanation: From X⁹₅, we can have the information as:
X — element
5 — Atomic number
9 — Mass number
The electronic configuration of X is 2, 3.

Group number is found out on the basis of valance electrons. Valence electrons are 3 so group number is 10 + 3 = 13.

The period can be found out by knowing the number of shells. Since the number of shells is 2 so it belongs to period 2.

Valence Electron Calculator – This free calculator provides you with free information about Valence Electron.

Periodic Classification Of Elements MCQ Question 6.
The elements A, B, C, D and E have atomic number 9, 11, 17, 12 and 13 respectively.
Which pair of elements belongs to the same group?
(a) A and B
(b) B and D
(c) A and C
(d) D and E
Answer:

MCQ Of Periodic Classification Of Elements Question 7.
An element ‘X‘ with atomic number 11 forms a compound with element ‘V with atomic number 8. The formula of the compound formed is:
(a) XY
(b) X₂Y
(c) XY₂
(d) X₂Y₃
Answer:
(b) X₂Y

Element X can lose one electron and has a configuration like that of Neon.
X → X⁺ + e^–
Element Y can gain two electrons to acquire noble gas configuration like that of Neon:
Y + 2e^– → Y₂^–
Or we can write

Periodic Table MCQ Questions And Answers Question 8.
The positions of four elements A, B, C, and D in the modern periodic table are shown below.

Which element is most likely to form an acidic oxide?
(a) A
(b) B
(c) C
(d) D
Answer:

Chapter 5 Science Class 10 MCQ Question 9.
In Mendeleev’s periodic table, gaps were left for the elements to be discovered later. Which of the following element found a place in the periodic table later?
(a) Germanium
(b) Chlorine
(c) Oxygen
(d) Silicon
Answer:

Class 10 Science Ch 5 MCQ Question 10.
Elements P, Q, R, and S have atomic numbers 11,15,17 and 18 respectively. Which of them are reactive non-metals?
(a) P and Q
(b) P and R
(c) Q and R
(d) R and S
Answer:
(c) Q and R

Chapter 5 Class 10 Science MCQ Question 11.
An element which is an essential constituent of all organic compounds belongs to:
(a) Group 1
(b) Group 14
(c) Group 15
(d) Group 16
Answer:

MCQs Of Periodic Classification Of Elements Question 12.
According to Mendeleev’s periodic law, the elements were arranged in the periodic table in the order of:
(a) Increasing atomic number
(b) Decreasing atomic number
(c) Increasing atomic masses
(d) Decreasing atomic masses
Answer:
(c) Increasing atomic masses

Explanation: Mendeleev’s periodic law is an arrangement of elements in increasing order of their atomic masses as Mendeleev’s periodic law states that, the physical and chemical properties of elements are a periodic function of their atomic masses.

Class 10 Chapter 5 Science MCQ Question 13.
Which of the following is the outermost shell for elements of period 2?
(a) K shell
(b) L shell
(c) M shell
(d) N shell
Answer:

MCQ Periodic Classification Of Elements Question 14.
Which of the following gives the correct increasing order of the atomic radii of O, F, and N?
(a) O, F, N
(b) N, F, O
(c) O, N, F
(d) F, O, N
Answer:

Periodic Table Class 10 MCQ Question 15.
Arrange the following elements in the order of their decreasing metallic character Na, Si, Cl, Mg, Al:
(a) Cl > Si > Al > Mg > Na
(b) Na > Mg > Al > Si > Cl
(c) Na > Al > Mg > Cl > Si
(d) Al > Na > Si > Ca > Mg
Answer:

Question 16.
Which among the following elements has the largest atomic radii?
(a) Na
(b) Mg
(c) K
(d) Ca
Answer:
(c) K

Explanation: Na and Mg belong to the same period, whereas Na and K are in the same group. In a group from top to bottom, the atomic radius increases, whereas it decreases in a period from left to right. Hence, the order would be K > Na > Mg and K > Ca > Mg.

Related Theory:
Atomic radius represents the distance from the nucleus to the outer shell of an element.
The trend of the atomic radius in the periodic table:

decreases going from left to right of a period
increases going down a group.

Question 17.
The electronic configurations of three elements X, Y and Z are:
X : 2 Y: 2, 8, 7 Z : 2, 8, 2
Which of the following is correct regarding these elements?
(a) X is a metal
(b) Y is a metal
(c) Z is a non-metal
(d) Y is a non-metal and Z is a metal
Answer:
(d) Y is a non-metal and Z is a metal.

Explanation: Element Y has 1 less electron to complete its octet which is a property of non-metals. On the other hand, element Z has 2 extra electrons to become stable which is a property of metals..

Question 18.
Which of the following elements would lose an electron easily?
(a) Mg
(b) Na
(c) K
(d) Ca
Answer:

Question 19.
Which of the following elements does not lose an electron easily?
(a) Na
(b) F
(c) Mg
(d) Al
Answer:
(b) F

Explanation: Flourine has 7 electrons in the outermost orbit. Its atom size is the smallest too. Since it is the most electronegative element, it does not lose an electron easily. Sodium has one valence electron, magnesium has 2 valence electrons, and aluminium has 3 valence electrons. All these metals lose electrons easily.

Related Theory
Metals can easily lose electrons and exhibit electropositive nature, whereas non-metals have a tendency to accept electrons and exhibit electronegative nature. Na, Al, and Mg are metals, whereas F is non-metal.

Question 20.
What type of oxide would Eka-aluminium form?
(a) EO₃
(b) E₃O₂
(c) E₂O₃
(d) EO
Answer:

Question 21.
The element with atomic number 14 is hard and forms acidic oxide and a covalent halide. To which of the following categories does the element belong?
(a) Metal
(b) Metalloid
(c) Non-metal
(d) Left-hand side element
Answer:
(b) Metalloid

Explanation: Atomic number 14 (electronic configuration of 2,8,4) is for silicon element, which is a metalloid and exhibits properties of both metal and non-metal. It has 4 electrons in its valence shell, so it tends to form covalent acidic oxide.

Question 22.
Which one of the following depicts the correct representation of atomic radius (r) of an atom?

(a) (I) and (II)
(b) (II) and (III)
(c) (III) and (IV)
(d) (I) and (IV)
Answer:
(b) (II) and (III)

Explanation: The distance between the center of the nucleus and the outermost shell is known as atomic radius.

Question 23.
Which one of the following does not increase while moving down the group of the periodic table?
(a) Atomic radius
(b) Metallic character
(c) Valence
(d) Number of shells in an element
Answer:

Question 24.
On moving from left to right in a period in the periodic table, the size of the atom:
(a) increases
(b) decreases
(c) does not change appreciably
(d) first decreases and then increases
Answer:
(b) decreases

Explanation: As we move from left to right in the period of periodic table, the number of shell remains same but atomic number increases. So, the increase in nuclear charge which tends to pull electrons closer to the nuclers and reduces the size of the atoms.

Related Theory
The size of atom of an inert gas is bigger than that of the preceding halogen atom. The greater size of the inert gas atom in a period is due to the structural stability of its outermost shell consisting of an octet of electrons.

Question 25.
Which of the following set of elements is written in order of their increasing metallic character?
(a) Be, Mg, Ca
(b) Na, Li, K
(c) Mg, Al, Si
(d) C, O, N
Answer:
(a) Be, Mg, Ca.

Explanation: As we move down in a group, the metallic nature of elements increases. Be, Mg, and Ca are present in the same group (group 2 of the modern periodic table). Thus, Ca has the highest metallic character.

Question 26.
An element X makes an oxide with the formula X₂O₃. This element will be in the same group as:
(a) Na
(b) Mg
(c) Al
(d) Cl [Diksha]
Answer:
(c) Al

Explanation: The answer is Al (aluminium). The element Al is in group II! of Mendeleev’s periodic table, in which the general formula of the oxides of elements is X₂O₃.

Question 27.
The two pairs of elements placed by Newlands in one slot are:
(a) Co, Ni and Ce, La
(b) Be, Mg and Co, Ni
(c) F, Cl, and Ce, La
(d) Zn, Sr, and Be, Mg
Answer:

Question 28.
The order of metallic character of some elements is: N < P < As < Sb < Bi. Identify the most electronegative among these elements,
(a) N
(b) P
(c) Sb
(d) Bi
Answer:
(a) N

Explanation: The less metallic an element, the more electro-negative it will be. Since electronegativity is the ability of an atom to gain electrons, whereas metallic character is related to the ability of atoms to lose electrons. As N is the least metallic of the given elements, it will be the most electronegative.

Question 29.
Four elements P, Q, R and S have number of valence electrons 2,3,5 and 7 respectively. A student noted down the Group number in Modern Periodic Table and their valency as:

Select the row containing the correct group number and valency.
Answer:

Question 30.
Consider the elements Li, Be, B, C, N, O and F.
(I) The most electropositive element is F.
(II) The most electronegative element is F.
(III) The only metalloid is B.
(IV) The smallest atomic size is Li.
Read the statements given above and select the incorrect statements:
(a) Both (I) and (III)
(b) Both (I) and (IV)
(c) Both (II) and (III)
(d) Both (II) and (IV)
Answer:
(b) Both (I) and (IV)

Explanation: Let us arrange the given elements according to their atomic number:
Li < Be < B < C < N < 0 < F.

All the above elements have two occupied shells and are therefore placed in the second group of the periodic table.

The most electropositive element is Li and the most electronegative element is F. This is because the tendency to lose electrons decreases as we go from left to right along a period. Also, as we go from left to right along a period, the atomic radius and hence the atomic size decreases because of the increase in effective nuclear charge experienced by the valence electrons. The only metalloid is B.

Question 31.
Out of the elements F, Cl, Br and I, which is the most electronegative element?
(a) F
(b) Cl
(c) Br
(d) I
Answer:
(a) F

Explanation: The electronegativity decreases as we move down a group because the ability to gain electrons decreases down a group. This is because of the decrease in the effective nuclear charge experienced by the valence electrons since a new shell is added in each group.

Since F, Cl, Br and I have 2, 3, 4 and 5 shells respectively, F is the most electronegative of these elements.

Assertion Reasoning questions Class 10 Science Chapter 5

For the following questions, two statements are given-one labeled Assertion (A) and the other labeled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below:
(a) Both (A) and (R) are true and (R) is the correct explanation of the assertion.
(b) Both (A) and (R) are true but (R) is not the correct explanation of the assertion.
(c) (A) is true but (R) is false.
(d) (A) is false but (R) is true.

Question 32.
Assertion (A): Potassium has a bigger atomic radius than lithium.
Reason (R): Atomic radius decreases along a period.
Answer:

Question 33.
Assertion (A): Chemical properties of the elements belonging to the same group are the same.
Reason (R): Elements belonging to the same group possess the same number of valence electrons.
Answer:
(a) Both (A) and (R) are true and (R) is the correct explanation of A.

Question 34.
Assertion (A): Nitrogen is a non-metal.
Reason (R): Nitrogen has 5 valence electrons.
Answer:
(a) Both (A) and (R) are true and (R) is the correct explanation of (A)

Explanation: Non-metals are the elements that form negative ions by gaining electrons.

Electronic configuration of N = 2 5
k = 2
L = 5
It needs 3 electrons to complete its octet and achieve the same configuration as that of the inert gas neon.
N + 3e^–→ N^3-

Question 35.
Assertion (A): Newland’s law of Octaves worked well with lighter elements only.
Reason (R): Newland assumed that only 56 elements existed in nature.
Answer:

Question 36.
Assertion (A): A correct position could not be assigned to hydrogen in Mendeleev’s periodic table.
Reason (R): Mendeleev Periodic Law states that ‘the properties of elements are the periodic function of their atomic numbers.
Answer:
(c) (A) is true but (R) is false

Explanation: A correct position could not be assigned to hydrogen in the periodic table. The electronic configuration of hydrogen resembles that of alkali metals. Like alkali metals, hydrogen combines with halogens, oxygen and sulfur to form compounds having similar formulae.

On the other hand, just like halogens, hydrogen also exists as diatomic molecules and it combines with metals and non-metals to form covalent compounds.

Moreover, Mendeleev’s Periodic Law states that ‘the properties of elements are the periodic function of their atomic masses’.

Question 37.
Assertion (A): The elements Sodium (Na), Magnesium (Mg), Aluminium (Al) belong to the same group in Modern Periodic Table.
Reason (R): Atoms of different elements with the same number of occupied shells are placed in the same period.
Answer:

Question 38.
Assertion (A): Calcium (Atomic No. 20) is more metallic than Potassium (Atomic No. 19).
Reason (R): The tendency to lose electrons decreases as we move from left to right in a period.
Answer:
(c) (A) is false but (R) is true.

Explanation: Potassium (Atomic No. 19) is more metallic than Calcium (Atomic No. 20) as the tendency to lose electrons decreases as we move from left to right in a period.

The electronic configuration of Potassium is 2, 8, 8, 1 and that of Calcium is 2, 8, 8, 2. Therefore, the effective nuclear charge acting on the valence electrons of Calcium will be more than that of Potassium.

(Competency Based Questions (CBQs))

Question 1.
Sulphur is a multivalent non-metal, abundant, tasteless and and odorless. In its native form sulphur is a yellow crystalline solid. In nature it occurs as the pure element or as sulphide and sulphate minerals.Sulphur dioxide or sulphur dioxide is the chemical compound with the

formula SO₂. It is a toxic gas responsible for the smell of burnt matches. It is released naturally by volcanic activity and is produced as a by product of copper extraction and the burning of fossil fuels contaminated with sulphur compounds.
Identify the group and period of the Modern Periodic Table to which Sulphur belongs. Write any two properties exhibited by sulphur.
Answer:
The atomic number of sulphur is 16. It’s electronic configuration is (2, 8, 6). It belongs to group 16 and period 3 of the Modern Periodic Table.

Two properties exhibited by sulphur are allotropy and catenation.

Question 2.
Around the year 1800, only 30 elements were known. Dobereiner in 1817 and Newlands in 1866 tried to arrange the then known elements and framed laws which were rejected by the scientists. Even after the rejection of the proposed laws, many scientists continued to search for a pattern that correlated the properties of elements with their atomic masses.

The main credit for classifying elements goes to Mendeleev for his most important contribution to the early development of a Periodic table of elements wherein he arranged the elements on the basis of their fundamental property, the atomic mass and also on the similarity of chemical properties. The formulae of their hydrides and oxides were treated as basic criteria for the classification of the elements. However, Mendeleev’s classification also had some limitations as it could not assign the position to isotopes. He also left some gaps in the periodic table.
(A) State Mendeleev’s Periodic Law.
Answer:
Mendeleev’s Periodic Law: It states that the properties of elements are the periodic function of their atomic masses.

Related Theory
Mendeleev concluded that when elements are arranged in order of increasing atomic masses, similar properties of element repented after a definite gap of atomic masses. This repetition of similar properties after a definite gap of atomic masses is also called periodicity in properties.

(B) Why did Mendeleev leave some gaps in the Periodic table?
Answer:

(C) If the letter ‘R‘ was used to represent any of the elements in the group, then the hydride and oxide of carbon would respectively be represented as:
(a) RH₄, RO
(b) RH₄, RO₂
(c) RH₂, RO₂
(d) RH₂, RO
Answer:

(D) Isotopes are:
(a) Atoms of an element with similar chemical properties but different atomic masses.
(b) Atoms of different elements with similar chemical properties but different atomic masses.
(c) Atoms of an element with different chemical properties but same atomic masses.
(d) Atoms of different elements with different chemical properties but same atomic masses.
Answer:
(a) Atoms of an element with similar chemical properties but different atomic masses.

Explanation: Isotopes are the atoms of some element which have same atomic number but different mass number. They have same atomic number, same number of protons, same number of electrons and, same number of valence electrons. Valence electrons are responsible for the chemical properties of an element. Since isotopes of an element have same number of valence electrons. So they will have similar chemical properties.

Related Theory
Isotopes of chlorine are Cl-35 and Cl-37:

Hence, isotopes of chlorine Cl-35 and Cl-37 will have similar chemical properties.

Question 3.
Recently, two persons died in a major ammonia gas leakage at the Indian Farmers Fertilizer Cooperative Limited (IFFCO) unit at Prayagraj. The experts point out that ammonia is stored for industrial use in liquid form under high pressure or in gaseous form at low temperature, as was the case in the IFFCO unit where the accident took place. Ammonia is critical in the manufacturing of fertilizers, and is one of the largest-volume synthetic chemicals produced in the world.

What type of bond is present ammonia molecule? Wilt a solution of ammonia be a good conductor or poor conductor of electricity?
Answer:
Ammonia molecule NH3 is formed by the sharing of electrons between nitrogen and hydrogen atoms as shown below:

As electron pairs are shared between the three hydrogen atoms and the nitrogen atom, a solution of ammonia in water will be a poor conductor of electricity as there are no charged particles present in an ammonia molecule.

Question 4.
The following table shows a part of the periodic table in which the elements are arranged according to their atomic numbers. (The letters given here are not the chemical symbols of the elements):

(A) Which element has a bigger atom, a or f?
Answer:
a (size decreases from left to right in a period).

(B) Which element has a higher valency, k or o?
Answer:

Explanation:

it has to lose only one electron to acquire metallic character whereas k has to lose 3 electrons which requires a lot of energy as compared to element so element i is more metallic.

(D) Select a letter which represents a non-metal of valency 2.
Answer:

Question 5.
When Sam was walking along the street, he saw several beautiful and colourful signages. In the signage industry, neon signs are electric signs lighted by long luminous gas-discharge tubes that contain rarefied neon or other gases. They are the most common use for neon lighting, which was first demonstrated in a modern form in December 1910 by Georges Claude at the Paris Motor Show.

Where would you locate the element with electronic configuration 2, 8 in the modern periodic table?
(a) Group 8
(b) Group 2
(c) Group 18
(d) Group 10
Answer:
(c) Group 18
Explanation: The element with electronic configuration 2, 8 has an octet configuration, so it must be an inert gas, i.e., neon, which is placed in group 18.

Related Theory
Group 18 in the modern periodic table has noble gases (inert gases). Helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe) and radon (Rn) are present in group 18. The members of the group have eight electrons in their outermost orbit (except helium which has two electrons). Thus, they have a stable electronic configuration. These gases are chemically un-reactive, i.e., they don’t react with other elements to form compounds.

Question 6.
Atoms of eight elements A, B, C, D, E, F, G and H have the same number of electron shells but different number of electrons in their outermost shells. It was found that elements A and G combine to form an ionic compound. This ionic compound is added in a small amount to almost all vegetables and dishes during cooking. Oxides of elements A and B are basic in nature while those of elements E and F are acidic. The oxide of element D is, however, almost neutral.
Based on the above information, answer the following questions:
(A) To which group or period of the periodic table do these elements belong?
Answer:

(B) What would be the nature of compound formed by a combination of elements B and F?
Answer:
The compound between B and F will be ionic in nature.

(D) Which one of the eight elements is most likely to be found in gaseous state at room temperature?
Answer:
Element H will be found in gaseous state at room temperature as it is the 8th element of the group so it would have 8 electrons in its outermost shell which is the electronic configuration of a nobel gas.

Related Theory:
Sodium chloride is used in almost all vegetables and dishes during cooking. It means A is sodium and G is chlorine.
Metals are one present on the left hand side of modern periodic table and non-metals on the right hand side. As we know oxides of metals are basic in nature and oxides of non-metals form acidic oxide. The elements given one.

Question 7.
Analyse the following table given below and answer the questions that follow:
Given alongside is a part of the periodic table. As we move vertically downward from Li to Fr:

Li	Be
Na
K
Rb
Cs
Fr	Ra

(A) Which among the following has larger size of atoms?
(a) Li
(b) Na
(c) Cs
(d) Fr
Answer:
(d) Fr

Explanation: Fr has greater atomic size as the atomic size increases gradually from lithium to francium.

(B) Which one of the following does not increase while moving down in group of the periodic table?
(a) Atomic radius
(b) Metallic character
(c) Valence
(d) Number of shells in an element
Answer:

(C) Name two properties of elements whose magnitude change while going from top to bottom in a group of the periodic table. In what manner do they change?
Answer:

(D) Rewrite the following statement after correction, if necessary:
“Groups have elements with consecutive atomic numbers”
Answer:
Periods have elements with consecutive atomic numbers.

Question 8.
In addition to its applications in electronic devices, germanium is used as a component of alloys and in phosphors for fluorescent lamps. Because germanium is transparent to infrared radiation, it is employed in equipment used for detecting and measuring such radiation, such as windows and lenses. Silicon is used in building and construction, able to bond materials such as concrete, glass, granite, steel and plastics, enabling them to work better and last longer. Solar cells made out of silicon currently provide a combination of high effciency, low cost, and long lifetime.

Three elements B, Si and Ge are:
(a) Metals
(b) Non-metals
(c) Metalloids
(d) Metal, non-metal and metalloid respectively
Answer:
(c) Metalloids

Explanation: The elements boron (B), silicon (Si) and germanium (Ge) exhibit intermediate properties of metals and non-metals, therefore, they are called as metalloids. These elements are placed in between metals and non-metals diagonally as a zigzag line to separate them.

Related Theory
A few other elements are arsenic (As), antimony (Sb), tellurium (Te), polonium (Po) and astatine (At).

Question 9.
Analyse the following table given below and answer the questions that follow:
The atomic radii of the element of the second period are given below:

(A) Arrange these elements in decreasing order of their atomic radii.
Answer:
Elements in decreasing order of their atomic radii

(B) Why does atomic radius decreases as we move from left to right in a period?
Answer:

(C) Which is not true about the noble gases?
(a) They are non-metallic in nature
(b) They exist in atomic form
(c) They are radioactive in nature
(d) Xenon is the most reactive among these
Answer:
(c) They are radioactive in nature.
Explanation: Noble gases are inert and are not radioactive in nature.

Related Theory
Noble gases cannot lose or gain or shore electrons as their outermost shell is complete.
He has 2 electrons in its K shell, which is completely filled as K shell can accommodate maximum of 2 electrons whereas Ne has 8 electrons in its L shell and its octet is complete so they exist in atomic form.

(D) Which of the following is the outermost shell for elements of period 2?
(a) K shell
(b) L shell
(c) M shell
(d) N shell
Answer:

Question 10.
A student tried to assign a correct position to hydrogen in Mendeleev’s Periodic Table by looking at its resemblance to alkali metals and the halogen family.
Another student wondered where she would place the isotopes of chlorine, Cl-35 and Cl-37 as they were atoms of the same element.

(A) No fixed position could be given to hydrogen in the Mendeleev’s Periodic Table as:
(I) Electronic configuration of hydrogen resembles that of alkali metals.
(II) Hydrogen combines with metals and non-metals to form ionic compounds.
(III) Hydrogen exists as diatomic molecules just like alkali metals.
(IV) Hydrogen combines with halogens, oxygen and sulphur to form compounds having similar formulae as alkali metals.
(a) Both (I) and (II)
(b) Both (II) and (III)
(c) Both (I) and (IV)
(d) Both (III) and (IV)
Answer:
(c) Both (I) and (IV)

Explanation: As Mendeleev’s periodic table was based on atomic mass, no fixed position could be assigned to hydrogen. However, it has one valence electron just like alkali metals Li, Na, K etc. Moreover, hydrogen combines with haLogens, oxygen and sulphur just like alkali metals do. However, hydrogen combines with metals and non-metals to form covalent bonds by sharing of electrons and exists as diatomic molecules like halogens.

(B) The formula of hydrides of elements belonging to a Group of Mendeelev’s Periodic Table is RH2. The Group Number to which the element belongs is:
(a) Group IV
(b) Group V
(c) Group VI
(d) Group VII

(C) The formula of oxides and hydrides of elements belonging to different Groups of the Mendeleev’s Periodic Table is given below:

The letter ‘R’ is used to represent any of the elements in the group.
Select the row containing incorrect information.
Answer:
(a) Croup No.: 1, Formula of oxides; RO, Formula of Hydrides; RH Explanation: The formula of hydrides and oxides of elements belonging to group I of Mendeleev’s table is R₂O and RH respectively. For example, formula of oxide and hydride of element Li will be Li₂O and LiH respectively.

(D) Select the correct statement regarding position of isotopes in Mendeleev’s Periodic Table:
(a) Mendeleev left some gaps in his periodic table for the isotopes.
(b) Isotopes were discovered after Mendeleev had proposed his periodic classification of elements.
(c) Mendeleev placed both the isotopes of chlorine (Cl-35 and Cl-37) under the same slot as they had same chemical properties.
(d) Mendeleev placed both the isotopes of chlorine (Cl-35 and Cl-37) in different slots as they had different masses.

(E) Mendeleev left some gaps in his Periodic Table as he predicted the existence of some elements that had not been discovered at that time. Which of the following elements discovered later, have properties similar to Eka-boron?
(a) Gallium
(b) Germanium
(c) Caesium
(d) Scandium
Answer:

Question 11.
We all have heard about the damage being done to the Taj Mahal and our environment due to high levels of oxides of certain elements in the atmosphere. Acid rain is caused by a chemical reaction that begins when these oxides are released into the air. These substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain.

Which of the following elements will form an acidic oxide?
(a) An element with atomic number 7
(b) An element with atomic number 3
(c) An element with atomic number 12
(d) An element with atomic number 19
Answer:
(a) An element with atomic number 7

Explanation: Non-metals form acidic oxides. The element with atomic number 7 is a non-metal (nitrogen). Rest three elements with atomic numbers, 3 (Li), 12 (Mg) andl9 (K) are metals and hence, form basic oxides.

Question 12.
Atomic radii of the elements of the second period are given below:
Period II elements: B Be O N Li C
Atomic radius (pm): 88 111 66 74 152 77
Atomic radii of first group elements are given below and arrange them in an increasing order.
Group 1 Elements 6: Na Li Rb Cs K
Atomic Radius (pm): 186 152 244 262 231
(A) Select the incorrect statements:
(I) The atomic radius decreases in moving from left to right along a period.
(II) The atomic radius increases in moving from left to right along a period
(III) As we move from left to right along a period, there is an increase in nuclear charge which tends to pull the electrons closer to the nucleus.
(IV) As we move from left to right along a period, there is a decrease in nuclear charge which tends to pull the electrons away from the nucleus.
(a) Both (I) and (III)
(b) Both (II) and (III)
(c) Both (I) and (IV)
(d) Both (II) and (IV)
Answer:
(d) Both (II) and (IV)

Explanation: As we move from left to right along a period we see that the atomic radius decreases. This is due to an increase in nuclear charge which tends to pull the electrons closer to the nucleus and reduces the size of the atom.

(B) Two students recorded their observations on variation of atomic radii of first group elements as given below:

First Student	Second Student
(a) Li has the smallest atomic radii	Na has the smallest atomic radii
(b) Atomic radius of Rb > Cs	Atomic radius of Cs > Rb
(c) Cs has the biggest atomic radius	Li has the smallest atomic radius
(d) Atomic radius of K > Na	The atomic radius of Na > K

Select the row containing the correct observation by both students.
Answer:
(c) First student: Cs has the biggest atomic radius, Second student: Li has the smallest atomic radius.

Explanation: The atomic radius and hence the atomic size increases as we move down a group. This is because a new shell is added as we move down the group. This increases the distance between the nucleus and the valence shell.

As Cs lies at the bottom of group 1, and Li lies at the top, Cs has the biggest atomic radius among Group 1 elements.

(C) The atomic size of Na is greater than Li because:
(a) Na has three shells, whereas Li has two shells in its atom
(b) The atomic number of Na is greater than Li
(c) As we go down a group, distance between outermost electrons and nucleus decreases.
(d) The mass of Na atom is greater than Li atom
Answer:

(D) The graph of variation of atomic radius with atomic number for alkali metals and halogens is shown below:

Select the correct observation:
(a) Na has a bigger atomic radius than Li due to decrease in nuclear charge
(b) F has a smaller atomic radius than Li due to increase in nuclear charge
(c) Na and Cl belong to the third period of Modern Periodic Table and have identical electronic configuration.
(d) Elements of Group 17 have the biggest atomic size in their respective periods.
Answer:
(b) F has a smaller atomic radius than Li due to increase in nuclear charge

Explanation: Both F and Li lie in the second period as they have two occupied shells. However, as the effective nuclear charge is more in the case of F as compared to Li, F has a smaller atomic radius than Li.

The atomic radius decreases in moving from left to right along a period and it increases in going from top to bottom along a group.

(E) The correct increasing order of the atomic radii of the elements Mg, Si and Cl is:
(a) Mg > Si > Cl
(b) Si < Cl < Mg
(c) Cl < Si < Mg
(d) Cl < Mg < Si
Answer:

Question 13.
Chemists have always looked for ways of arranging the elements to reflect the similarities between their properties. The earliest attempt to classify the elements was in 1789, when Antoine Lavoisier grouped the elements based on their properties into gases, non-metals, metals and earths. Several other attempts were made to group elements together over the coming decades. In 1829, Johann Dobereiner recognised triads of elements with chemically similar properties, such as lithium, sodium and potassium, and showed that the properties of the middle element could be predicted from the properties of the other two. It was not until a more accurate list of the atomic mass of the elements became available at a conference in Karlsruhe, Germany in 1860 that real progress was made towards the discovery of the modern periodic table.
(A) Which of the following elements form Dobereiner’s triads?
(a) Li, Na, K
(b) Ca, Sr, Ba
(c) F, Cl, Br
(d) Cl, Br, I
Answer:

(B) Given below are four statements on Dobereiner’s triads:
(I) One triad identified by Dobereiner was (Ca, Na, Ba)
(II) The triads identified by Dobereiner had three elements each.
(III) The atomic mass of the middle element was roughly equal to the atomic masses of the other two elements.
(IV) Dobereiner could identify only three triads from the elements known at that time.
Identify the incorrect statements.
(a) Both (I) and (III)
(b) Both (II) and (III)
(c) Both (I) and (IV)
(d) Both (II) and (IV)
Answer:
(a) Both (I) and (III)

Explanation: Dobereiner’s triods consisted of three elements having simiLar properties. He coutd identifij onLy three triads out of the elements discovered at that time. They were (Li, Na, K), (Ca. Sr. Ba) and (Cl, Br, I). The atomic mass of the middle element was roughly equal to the average of the atomic masses of the other two elements.

(C) A & B are two elements having similar properties which obey the law of octaves. How many elements are there in between A and B?
(a) 5
(b) 6
(c) 7
(d) 8

(D) Which of the following is not a limitation of Newland’s law of octaves:
(a) The elements fluorine, chlorine and bromine are placed in the same column (musical note).
(b) Newlands’ Law of Octaves worked well with lighter elements only.
(c) Newlands assumed that only 56 elements existed in nature and no more elements would be discovered in the future.
(d) In order to fit elements into his Table, Newlands adjusted cobalt and nickel in the same slot.
Answer:
(a) The elements fluorine, chlorine and bromine are placed in the same column (musical note).

Explanation: The elements fluorine, chlorine and bromine are placed in the some column (musicol note) as they have similar properties and are known as halogens. Even in the modern periodic table, they are placed in the same group, group 17.

(E)Given below are few observations on properties of eLements.

Select the option containing the correct observation.
Answer:
(d) Observation: Properties of Li and Na were found to be similar, Doberimer’s Triods: Yes, NewLands’ Law Yes.

Explanation: Both Be and Mg were placed under the same note in Newland’s law, but were not part of Döbereiner’s triads. Dobereiners Triads

Question 14.
Valency of an element is the combining capacity of an atom of the element. The volency of an element is related to how many electrons are in the outer shell. The chemical formula for a substance shows how many atoms of each element are present in a molecule, or the proportion of atoms of each element. The formula can be worked out using the volency.

The molecular formula of a compound can be predicted knowing the valency of the constituting atoms. Knowledge of valency is useful in calculating equivalent weight of elements, writing down chemical equations and in checking the structures of molecules. Some elements show variable valency and the valency determines the properties of elements. The table below gives atomic number of five elements written as P, Q, R, S and T, which are not their real chemical symbols.

Element	Atomic Number
P	4
Q	9
R	14
S	18
T	20

(A) The valency and group number in Modern Periodic Table of four elements are given below:

Select the option containing the correct valency and group number.
Answer:

(B) The electronic configuration of the element T is:

(C) The valency of elements:
(a) Decreases as we go down a group
(b) Remons same in a group
(c) Increases as we go down a group
(d) First increases and then decreases as we go down a group
Answer:
(b) Remains same in a group

Explanation: The valency of elements is equal to the number of valence electrons in case of metals and (8 – valence electrons) for non-metals. Moreover, all elements belonging to the same group have same outer shell electronic configuration. Therefore, valency of elements remains same in a group.

(D) As per the table given above, the element(s) which wilL form only covaLent bonds ¡s:
(I) P
(II) R
(III) S
(IV) Q
(a) Only (I)
(b) Only (II)
(c) Both (I) and (IV)
(d) Both (II) and (III)
Answer:

(E) Select the incorrect statement:
(a) Valency of elements of second period is 2.
(b) Valency of an element is determined by the number of valence electrons present in the outermost shell of its atom.
(c) Valency of metals is equal to the number of valence electrons.
(d) Valency of elements of Group 18 of Modern Periodic Table is 0.
Answer:

Question 15.
The elements can be classified as metals, nonmetals, or metalloids. In the Modern Periodic Table, a zig-zag line separates metals from non-metals.

The metals are to the Left of the line (except for hydrogen, which is a nonmetaL), the nonmetals are to the right of the Line, and the elements immediately adjacent to the line are the metalioids.
Ionization energy is the minimum amount of energy required to remove the most loosely bound electron of an isolated neutral gaseous atom or molecule. It is expressed as
X(g) + energy → X⁺(g) + e^–

where X is any atom or molecule, X+ is the ion with one electron removed, and e- is the removed electron.
Since the metals are further to the left on the periodic table, they have low ionization energies.
(A) Which of the following elements is not a metalloid?
(a) Si
(b) Ge
(c) As
(d) Ar
Answer:
(d)Ar

Explanation: The metalloids are B, Si. Ge, As, Te and Po. Ar (Argon) is a noble gas having atomic number 18.

(B) An element A (atomic number 17) reacts with an element B (atomic number 14) to form a tetravalent halide.
Select the option which gives the correct nature of elements A and B:

Element A	Element B
(a) Metal	Non-metal
(b) Non-metal	Non-metal
(c) Non-metal	Metalloid
(d) Metalloid	Metalloid

Answer:

(C) Four statements are given below.
(I) The metalloids are placed in Groups 13 – 16 in the Modern Periodic Table
(II) Boron is the only metalloid in group 13 of the Modern Periodic Table.
(III) Group 14 of the Modern Periodic Table contains only metalloids.
(IV) Group 17 of the Modern Periodic Table contains both metalloids and non-metals
Select the correct statement(s):
(a) Both (I) and (II)
(b) Both (I) and (III)
(c) Both (II) and (IV)
(d) (I), (II) and (IV)
Answer:

(D) Variation of the ionization energy of elements with atomic number upto atomic number 20 is given below:
From the graph we can conclude that the tendency to lose electrons:
(a) Increases as we go down the group
(b) Decreases as we go down the group
(c) Remains constant in a group
(d) No definite conclusion can be made
Answer:

(E) The metalloid which is the second most abundant element on earth’s crust after oxygen and is widely used in electronics is:
(a) B (b) Ge
(c) Si (d) As
Answer:

Very Short Answer Type Questions

Question 1.
State the common characteristic of the following elements: Boron, Silicon, Germanium and Arsenic
Answer:

Question 2.
State the Periodic Law on which the Modern Periodic Table is based.
Answer:
Periodic Law on which the Modern Periodic Table is based is termed as Modern Periodic Law. According to Modern Periodic Law – The properties of elements are a periodic function of their atomic numbers.

Related Theory
Modern Periodic Table or Long form of Periodic table was prepared by Henry Moseley and is based on electronic configuration of elements. The elements are arranged in increasing order of their atomic numbers. Modern Periodic Table consists of 18 vertical columns called 7 horizontal rows called periods.

Question 3.
How many metals are present in second period of periodic table?
Answer:

Question 4.
The atomic radii of three elements A, B and C of a periodic table are 186 pm, 104 pm and 143 pm respectively. Giving a reason, arrange these elements in the increasing order of atomic numbers in the period.
Answer:
Since atomic size decreases along a period and the atomic number increases. So, the element with smaller radii, has the highest atomic number.

Hence, B has the highest atomic number followed by C and A i.e. A < C < B

Explanation: The atomic size is the distance between the centre of the nucleus and the outermost shell of an isolated atom. The atomic radius is measured in picometre, (1 pm = 10^-12 m).

The atomic radius decreases in moving from left to right along a period. This is due to:
As the atomic number increases, the nuclear charge increases. Increase in nuclear charge tends to pull the electrons closer to the nucleur and reduce the size of the atom.

Question 5.
Consider the following :
20Ca, 8O,16S, 4Be
Which of the above elements would you expect to. be in group 2 of the Modern Periodic table?
Answer:
Consider the electronic configuration of elements:
Ca: 2, 8, 8, 2 O: 2, 6 S: 2, 8, 6 Be: 2, 2
As Ca and Be all have the same number of valence electrons (2), they belong to group 2 of the Modern Periodic Table.

Question 6.
Define electropositivity.
Answer:
Electropositivity is the ability metals to lose electron to form positive ions.
Explanation: Metals have 1, 2, 3 valence electrons and have a strong tendency to lose these to form positive ions, so metal are called electropositive elements.
For example:

as we move down in a group in the periodic table, atomic size increases. As a result, force of attraction between the nucleus and valence electrons decreases.

Question 7.
Write two reasons responsible for the late discovery of noble gases
Answer:
The two reasons for the late discovery of noble gases are:

Their low concentration in the atmosphere.
Their chemical inertness or very less reactivity.

Question 8.
What were the criteria used by Mendeleev in creating has periodic table
Answer:
The criteria used by Mendeleev in creating his periodic table were the relationship between the atomic masses of the elements and their physical and chemical properties and formulae of the hydrides and oxides formed by an element.

MCQ Questions for Class 10 Science with Answers

Class 10 Science Chemistry MCQ:

MCQ Questions for Class 6 Science Chapter 1 Food Where Does It Come From with Answers

Food Where Does It Come From Class 6 MCQ Online Test With Answers Questions

October 18, 2024

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Class 6 Science Chapter 1 MCQ With Answers

Science Class 6 Chapter 1 MCQs On Food Where Does It Come From

Choose the correct option in the following questions:

Class 6 Science Chapter 1 MCQ Question 1.
Which part of a mustard plant is edible?
(a) Seeds and flowers
(b) Leaves and flowers
(c) Seeds and leaves
(d) Stem and roots

Answer

Answer:(c) Seeds and leaves
Explanation:
Seeds of mustard are used for oil and spices while leaves are used as
vegetables.

Food Where Does It Come From Class 6 MCQ Question 2.
Honey bees are often seen sitting on flowers. Why do they do so?
(a) They like flowers
(b) They lay eggs on flowers
(c) They suck nectar from flowers
(d) All of these

Answer

Answer: (c) They suck nectar from flowers
Explanation:
Bees collect nectar from flowers and convert it into honey.

MCQ Questions For Class 6 Science Chapter 1 Question 3.
Which one is the best for health?
(a) Boiled seeds
(b) Roasted seeds
(c) Wet swollen seeds
(d) Sprouted seeds

Answer

Answer: (d) Sprouted seeds
Explanation:
Sprouted seeds are the best for health.

Food Where Does It Come From MCQ Question 4.
Which one of the following set comprises only herbivorous animals?
(a) Cow, goat, rabbit, deer
(b) Cow, goat, rabbit, wolf
(c) Wolf, goat, rabbit, deer
(d) Cow, crow, crane, camel

Answer

Answer: (a) Cow, goat, rabbit, deer
Explanation:
Wolf and crow are not herbivorous.

Ncert Class 6 Science Chapter 1 MCQ Question 5.
Animals which eat both plants and flesh of other animals are called
(a) herbivores
(b) carnivores
(c) omnivores
(d) sanguinivores

Answer

Answer: (c) omnivores
Explanation:
Animals which eat both plants and flesh of other animals are called omnivores.

Class 6 Science Ch 1 MCQ Question 6.
Human beings are
(a) herbivores
(b) carnivores
(c) omnivores
(d) decomposers

Answer

Answer: (c) omnivores
Explanation:
Human beings eat herbs as well as meat and eggs.

MCQ Questions For Class 6 Science With Answers Chapter 1 Question 7.
Which one of the following sets is not correct?
(a) Cow, rabbit, deer, goat
(b) Tiger, lion, wolf, panther
(c) Bear, crow, cat
(d) Rabbit, deer, cat, wolf

Answer

Answer: (d) Rabbit, deer, cat, wolf
Explanation:
All other sets have only one type of animals.

Science Class 6 Chapter 1 MCQ Question 8.
Which one is not a food for a squirrel?
(a) Grains
(b) Small insects
(c) Fruits
(d) All of these

Answer

Answer: (b) Small insects
Explanation:
Squirrel is a herbivorous animal.

MCQ Class 6 Science Chapter 1 Question 9.
Rearing and management of fishes in large scale is called
(a) agriculture
(b) apiculture
(c) pisciculture
(d) horticulture

Answer

Answer: (c) pisciculture
Explanation:
Rearing and management of fishes is called pisciculture.

Class 6 Chapter 1 Science MCQ Question 10.
Which of the following is a root vegetable ?
(a) Potato
(b) Carrot
(c) Cucumber
(d) Onion

Answer

Answer: (b) Carrot
Explanation:
Carrot is a root.

Match the following items given in Column A with that in Column B:

Column A	Column B
Lion	Nectar
Deer	Fruit juice
Man	Human faecal
Female mosquito	Plants
Butterfly	Human blood
Human infant	Both plants and animals
Male mosquito	Animals
Pig	Mother’s milk

Answer

Answer:

Column A	Column B
Lion	Animals
Deer	Plants
Man	Both plants and animals
Female mosquito	Human blood
Butterfly	Nectar
Human infant	Mothers milk
Male mosquito	Fruit juice
Pig	Human feecal

Fill in the blanks with appropriate words:

1. We feel …………….. when we have no food for some time.

Answer

Answer: weak

2. ……………. living beings need food.

Answer

Answer: All

3. Children need food for ………………. .

Answer

Answer: growth

4. If food is not given for long, most of the known living beings will ……………. .

Answer

Answer: die

5. We get ……………… after eating food.

Answer

Answer: energy

6. Different organisms eat …………….. kinds of food.

Answer

Answer: different

7. Mustard ………………….. are used as spices and oil.

Answer

Answer: seeds

8. We get food from ………………… as well as animals.

Answer

Answer: Plants

9. We use ……………… energy when we run than when we walk.

Answer

Answer: more

10. We use ……………… energy when we sleep.

Answer

Answer: more

11. Each of us should make sure not to ……………… food.

Answer

Answer: waste

12. Human beings are ……………. .

Answer

Answer: omnivore

State -whether the statements given below are True or False:

1. Different people have different choices of food.

Answer

Answer: True

2. If a person does not get food he feels weak and is likely to fall ill.

Answer

Answer: True

3. Human beings, animals, birds, insects, etc. eat the same type of food.

Answer

Answer: False

4. There is no effect on our ability to do work even if we do not eat food for a day.

Answer

Answer: False

5. Lion is omnivorous.

Answer

Answer: False

6. Plants give us more varieties of food than animals.

Answer

Answer: True

7. Cooked food can be easily consumed and absorbed by our body.

Answer

Answer: True

8. There is a range of food items eaten over various states of India.

Answer

Answer: True

9. For every item that we eat there are a number of persons who have contributed.

Answer

Answer: True

10. Leaves absorb sunlight and prepare food using chlorophyll.

Answer

Answer: True

We hope the given NCERT MCQ Questions for Class 6 Science Chapter 1 Food Where Does It Come From with Answers Pdf free download will help you. If you have any queries regarding Food Where Does It Come From CBSE Class 6 Science MCQs Multiple Choice Questions with Answers, drop a comment below and we will get back to you soon.

Class 6 Science MCQ:

MCQ Questions for Class 7 Science Chapter 12 Reproduction in Plants with Answers

Reproduction in Plants Class 7 MCQ Online Test With Answers Questions

October 18, 2024

Check the below Online Education NCERT MCQ Questions for Class 7 Science Chapter 12 Reproduction in Plants with Answers Pdf free download. MCQ Questions for Class 7 Science with Answers were prepared based on the latest exam pattern. We have Provided Reproduction in Plants Class 7 Science MCQs Questions with Answers to help students understand the concept very well. https://ncertmcq.com/mcq-questions-for-class-7-science-with-answers/

You can refer to NCERT Solutions for Class 7 Science Chapter 12 Reproduction in Plants to revise the concepts in the syllabus effectively and improve your chances of securing high marks in your board exams.

Class 7 Science Chapter 12 MCQ With Answers

Science Class 7 Chapter 12 MCQs On Reproduction in Plants

Choose the correct answer:

Reproduction In Plants Class 7 MCQ Question 1.
Vegetative propagation in potato takes place by
(a) leaves
(b) stem
(c) root
(d) seed

Answer

Answer: (b) stem

Class 7 Science Chapter 12 MCQ Question 2.
In which of the following plants buds are present on the margins of leaves?
(a) Bryophyllum
(b) Touch me not
(c) Chandan
(d) Coriander

Answer

Answer: (a) Bryophyllum

Reproduction In Plants Class 7 MCQ With Answers Question 3.
In yeasts reproduction occurs by
(a) fragmentation
(b) binary fission
(c) budding
(d) spore formation

Answer

Answer: (c) budding

MCQ Questions For Class 7 Science Chapter 12 Question 4.
Which of the following parts of a plant take part in sexual reproduction?
(i) Flower
(ii) Seed
(iii) Fruit
(iv) Branch
Choose the correct answer from below:
(a) (i) and (ii)
(b) (i), (ii) and (iii)
(c) (iii) and (iv)
(d) (ii), (iii) and (iv)

Answer

Answer: (b) (i), (ii) and (iii)

MCQ On Reproduction In Plants Class 7 Question 5.
Lila observed that a pond with clear water was covered up with a green algae within a week. By which method of reproduction did the algae spread so rapidly ?
(a) Budding
(b) Sexual reproduction
(c) Fragmentation
(d) Pollination

Answer

Answer: (c) Fragmentation

Class 7 Science Ch 12 MCQ Question 6.
Seeds of drumstick and maple are carried to long distances by wind because they possess
(a) winged seeds
(b) large and hairy seeds
(c) long and ridged fruits
(d) spiny seeds

Answer

Answer: (a) winged seeds

Reproduction In Plants MCQ Class 7 Question 7.
The ‘eye of the potato plant is what
(a) the root is to any plant
(b) the bud is to a flower
(c) the bud is to Bryophyllum leaf
(d) the anther is to stamen

Answer

Answer: (c) the bud is to Bryophyllum leaf

Class 7 Reproduction In Plants MCQ Question 8.
The ovaries of different flowers may contain
(a) only one ovule
(b) many ovules
(c) one to many ovules
(d) only two ovules

Answer

Answer: (c) one to many ovules

Class 7 Science Chapter 12 MCQ Online Test Question 9.
Which of the following statements is/are true for sexual reproduction in plants?
(i) Plants are obtained from seeds
(ii) Two plants are always essential
(iii) Fertilisation can occur only after pollination
(iv) Only insects are agents of pollination
Choose from the options given below:
(a) (i) and (ii)
(b) (i) only
(c) (i) and (ii)
(d) (i) and (iv)

Answer

Answer: (a) (i) and (ii)

Ch 12 Science Class 7 MCQ Question 10.
Pollination refers to the:
(a) transfer of pollen from anther to ovary
(b) transfer of male gametes from anther to stigma
(c) transfer of pollen from anther to stigma
(d) transfer of pollen from anther to ovule

Answer

Answer: (c) transfer of pollen from anther to stigma

Match the following:

Column A	Column B
(i) Bread mould	(a) Cutting
(ii) Yeast	(b) Leaves
(iii) Potato	(c) Fragmentation
(iv) Bose	(d) Detached body part
(v) Sweet potato	(e) Spores
(vi) Bryophyllum	(f) Eye
(vii) Cactus	(g) Roots
(viii) Spirogyra	(h) Budding

Answer

Answer:

Column A	Column B
(i) Bread mould	(e) Spores
(ii) Yeast	(h) Budding
(iii) Potato	(f) Eye
(iv) Bose	(a) Cutting
(v) Sweet potato	(g) Roots
(vi) Bryophyllum	(b) Leaves
(vii) Cactus	(d) Detached body part
(viii) Spirogyra	(c) Fragmentation

Fill in the blanks:

1. In …………………. reproduction, one individual can produce many individuals from its body parts.

Answer

Answer: asexual

2. Both stamen and carpel are present in …………………. flowers.

Answer

Answer: bisexual

3. Budding is a type of …………………. reproduction.

Answer

Answer: asexual

4. The process of …………………. ensures continuity of life on the earth.

Answer

Answer: reproduction

5. …………………. are the reproductive parts of a plant.

Answer

Answer: Flowers

6. Buds in potato are also called ………………….

Answer

Answer: eyes

7. Plants produce seeds as a result of …………………. reproduction.

Answer

Answer: sexual

8. The small bulb like projection coming out from the yeast cell is called a ………………….

Answer

Answer: bud

9. The …………………. develops into an embryo.

Answer

Answer: zygote

10. The fruits are ripened ………………….

Answer

Answer: ovary

Choose the true and false statements from the following:

1. Two individuals are needed for a sexual reproduction.

Answer

Answer: True

2. Seed is the only structure which develops into new plant.

Answer

Answer: False

3. Plants such as cacti produce new plants when their parts get detached from the main plant body.

Answer

Answer: True

4. Plants produced by vegetative propagation take less time to grow and bear flower and fruit.

Answer

Answer: True

5. The spores are asexual reproductive bodies.

Answer

Answer: True

6. Anther contains female gametes called eggs.

Answer

Answer: False

7. The fruit is ripened ovary.

Answer

Answer: True

8. Seed dispersal in coconut is aided by winds.

Answer

Answer: False

9. Fusion of male and female gametes is called pollination.

Answer

Answer: False

10. A bisexual flower has both male and female reproductive parts.

Answer

Answer: True

We hope the given NCERT MCQ Questions for Class 7 Science Chapter 12 Reproduction in Plants with Answers Pdf free download will help you. If you have any queries regarding Reproduction in Plants CBSE Class 7 Science MCQs Multiple Choice Questions with Answers, drop a comment below and we will get back to you soon.

Class 7 Science MCQ:

MCQ Questions for Class 8 Science Chapter 8 Cell Structure and Functions with Answers

Cell Structure and Functions Class 8 MCQ Online Test With Answers Questions

October 18, 2024

Check the below Online Education NCERT MCQ Questions for Class 8 Science Chapter 8 Cell Structure and Functions with Answers Pdf free download. MCQ Questions for Class 8 Science with Answers were prepared based on the latest exam pattern. We have provided Cell Structure and Functions Class 8 Science MCQs Questions with Answers to help students understand the concept very well. https://ncertmcq.com/mcq-questions-for-class-8-science-with-answers/

You can refer to NCERT Solutions for Class 8 Science Chapter 8 Cell Structure and Functions to revise the concepts in the syllabus effectively and improve your chances of securing high marks in your board exams.

Class 8 Science Chapter 8 MCQ With Answers

Science Class 8 Chapter 8 MCQs On Cell Structure and Functions

Choose the correct option.

Class 8 Science Chapter 8 MCQ Question 1.
Nucleus is separated from cytoplasm by
(a) nuclear membrane
(b) nucleoplasm
(c) organs
(d) cell membrane

Answer

Answer: (a) nuclear membrane

Cell Structure And Function Class 8 MCQ Question 2.
The liquid material in the nucleus is
(a) chromosomes
(b) bacteria
(c) nucleoplasm
(d) nucleolus

Answer

Answer: (c) nucleoplasm

Class 8 Science Ch 8 MCQ Question 3.
Tissues combine to form
(a) nucleus
(b) cells
(c) organism
(d) organs

Answer

Answer: (d) organs

MCQ Questions For Class 8 Science Chapter 8 Question 4.
Cells present in living organism differ in
(a) numbers
(b) shape
(c) size
(d) all of these

Answer

Answer: (d) all of these

Class 8 Chapter 8 Science MCQ Question 5.
Cells which lack nuclear membrane are
(a) eukaryotic cells
(b) prokaryotic cells
(c) single cells
(d) multicells

Answer

Answer: (b) prokaryotic cells

Ncert Class 8 Science Chapter 8 MCQ Question 6.
The control centre of all the activities of a cell is
(a) nucleus
(b) nucleoplasm
(c) cytoplasm
(d) organelles

Answer

Answer: (a) nucleus

Class 8 Cell Structure And Function MCQ Question 7.
The coloured organelles which are found in plants only are
(a) chlorophyll
(b) plastids
(c) vacuoles
(d) WBC

Answer

Answer: (b) plastids

Cell Structure And Function MCQ Question 8.
Genes are located in
(a) chrpmosomes
(b) plastids
(c) cytoplasm
(d) lysosome

Answer

Answer: (a) chrpmosomes

Class 8 Ch 8 Science MCQ Question 9.
A group of similar cells combine to form
(a) tissue
(b) organ
(c) organisms
(d) organelles

Answer

Answer: (a) tissue

Ch 8 Science Class 8 MCQ Question 10.
The organism containing only a single cell is called
(a) unicellular organism
(b) multicellular organism
(c) organelle
(d) all of these

Answer

Answer: (a) unicellular organism

Chapter 8 Science Class 8 MCQ Question 11.
Cell walls is found in
(a) plant cells only
(b) animal cells only
(c) both (a) and (b)
(d) none of them

Answer

Answer: (a) plant cells only

Science Class 8 Chapter 8 MCQ Question 12.
The empty blank looking structures in the cytoplasm is
(a) vacuoles
(b) plastids
(c) plasma membrane
(d) nucleus

Answer

Answer: (a) vacuoles

Class 8th Science Chapter 8 MCQ Question 13.
The other name of cell membrane is
(a) plasma membrane
(b) cell wall
(c) nuclear membrane
(d) none of these

Answer

Answer: (a) plasma membrane

Class 8 Science Chapter 8 MCQs Question 14.
The basic structural and functional unit of all living organism is
(a) cell
(b) cell wall
(c) cell membrane
(d) chloroplasts

Answer

Answer: (a) cell

MCQ Cell Structure And Function Class 8 Question 15.
Chromosomes are found in
(a) nucleus
(b) nucleolus
(c) nucleoplast
(d) vacuole

Answer

Answer: (a) nucleus

Match the items given in column I suitably with those given in column II

Column I	Column II
1. Mitochondria	(a) Cell
2. Functional unit of life	(b) Nucleus
3. Control unit of cell	(c) Unicellular
4. Single-celled organism	(d) Discovery of cell
5. Robert Hooke	(e) Power house of a cell
6. Combination of tissues	(f) Transfers messages
7. Cytoplasm	(g) Jelly-like substance
8. Nerve cell	(h) Forms organ
9. Living substance in the cell	(i) Cell wall
10. Outermost thick layer in plant cells	(j) Protoplasm

Answer

Answer:

Column I	Column II
1. Mitochondria	(e) Power house of a cell
2. Functional unit of life	(a) Cell
3. Control unit of cell	(b) Nucleus
4. Single-celled organism	(c) Unicellular
5. Robert Hooke	(d) Discovery of cell
6. Combination of tissues	(h) Forms organ
7. Cytoplasm	(g) Jelly-like substance
8. Nerve cell	(f) Transfers messages
9. Living substance in the cell	(j) Protoplasm
10. Outermost thick layer in plant cells	(i) Cell wall

Fill in the blanks with suitable word/s.

1. Cells are the __________ unit of all living organisms.

Answer

Answer: basic

2. __________ cells are branched.

Answer

Answer: Muscle

3. Amoeba has __________ shape.

Answer

Answer: irregular

4. The __________ cell transfers the messages.

Answer

Answer: nerve

5. __________ is a group of tissues.

Answer

Answer: Organ

6. Protoplasm is __________ inside the cell.

Answer

Answer: viscous fluid

7. Eukaryotes cells have a well-developed __________.

Answer

Answer: nucleus

8. The jelly-like substance found between the nucleus and the cell-membrane is __________

Answer

Answer: cytoplasm

9. Nucleus is separated from the cytoplasm by __________.

Answer

Answer: nuclear membrane

10. An __________ is a group of organs.

Answer

Answer: organ system

11. __________ are present in plant cells but in animal cells.

Answer

Answer: Plastids, absent

12. __________ is the process of making food in plants.

Answer

Answer: Photosynthesis

13. __________ is absent in animal cell.

Answer

Answer: Cell wall

14. The kitchen of plant cell is __________.

Answer

Answer: plastid

15. __________ is the power house of the cell.

Answer

Answer: Mitochondria

State whether the given statements are true or false.

1. Cytoplasm is not a part of cell.

Answer

Answer: False

2. Cell wall surrounds the cell membrane.

Answer

Answer: True

3. A group of similar cells is called tissue.

Answer

Answer: True

4. Tissues combine to form an organism.

Answer

Answer: False

5. Cell are of different sizes.

Answer

Answer: True

6. Chloroplasts are blue in colour.

Answer

Answer: False

7. Plastid occur in plant cells only.

Answer

Answer: True

8. Chromosomes contain basic hereditary units called genes.

Answer

Answer: True

9. Nucleus is the control unit of cell.

Answer

Answer: True

10. The shape and size of cell is related to its function.

Answer

Answer: True

11. Organs make up tissues.

Answer

Answer: False

12. The cytoplasm and nucleoplasm make up the protoplasm.

Answer

Answer: True

13. The smallest unit of life is chloroplast.

Answer

Answer: False

14. Unicellular organisms have one-celled body.

Answer

Answer: True

15. The cell wall is living in nature.

Answer

Answer: False

We hope the given NCERT MCQ Questions for Class 8 Science Chapter 8 Cell Structure and Functions with Answers Pdf free download will help you. If you have any queries regarding Cell Structure and Functions CBSE Class 8 Science MCQs Multiple Choice Questions with Answers, drop a comment below and we will get back to you soon.

Class 8 Science MCQ:

MCQ Questions for Class 8 Science Chapter 17 Stars and the Solar System with Answers

Stars and the Solar System Class 8 MCQ Online Test With Answers Questions

October 18, 2024

Check the below Online Education NCERT MCQ Questions for Class 8 Science Chapter 17 Stars and the Solar System with Answers Pdf free download. MCQ Questions for Class 8 Science with Answers were prepared based on the latest exam pattern. We have provided Stars and the Solar System Class 8 Science MCQs Questions with Answers to help students understand the concept very well. https://ncertmcq.com/mcq-questions-for-class-8-science-with-answers/

You can refer to NCERT Solutions for Class 8 Science Chapter 17 Stars and the Solar System to revise the concepts in the syllabus effectively and improve your chances of securing high marks in your board exams.

Class 8 Science Chapter 17 MCQ With Answers

Science Class 8 Chapter 17 MCQs On Stars and the Solar System

Choose the correct option in the following questions:

Stars And Solar System Class 8 MCQ Question 1.
Which of the following does not belong to the family of solar system?
(a) Planet
(b) Galaxy
(c) Meteors
(d) Comet

Answer

Answer: (b) Galaxy

Class 8 Science Chapter 17 MCQ Question 2.
The Halley’s Comet is seen after every
(a) 76 months
(b) 76 years
(c) 56 months
(d) 56 years

Answer

Answer: (b) 76 years

Stars And The Solar System Class 8 MCQ Question 3.
Ursa Major is a
(a) star
(b) constellation
(c) seen only with telescope
(d) satellite

Answer

Answer: (b) constellation

Class 8 Science Ch 17 MCQ Question 4.
Which planet has the largest number of satellites?
(a) Jupiter
(b) Saturn
(c) Mercury
(d) Mars

Answer

Answer: (b) Saturn

Star And Solar System Class 8 MCQ Question 5.
Which unit is used to measure astronomical distances?
(a) Leap year
(b) Light year
(c) Century
(d) Sound year

Answer

Answer: (b) Light year

Class 8 Stars And Solar System MCQ Question 6.
The stars forming a recognizable shape is called
(a) constellation
(b) system
(c) galaxy
(d) asteroids

Answer

Answer: (a) constellation

MCQ Questions For Class 8 Science Chapter 17 Question 7.
Which star is nearest to Earth?
(a) Pole star
(c) Orion
(b) Cassiopeia
(d) Sun

Answer

Answer: (d) Sun

MCQ On Stars And Solar System Question 8.
What term is used for celestial bodies that revolve around the Sun in highly elliptical orbit?
(a) Comet
(b) Meteors
(c) Asteroids
(d) Planets

Answer

Answer: (a) Comet

MCQ On Stars And Solar System For Class 8 Question 9.
Which small objects revolve between the orbits of Mars and Jupiter?
(a) Satellites
(b) Comets
(c) Asteroids
(d) Meteorites

Answer

Answer: (c) Asteroids

Stars And Solar System MCQ Class 8 Question 10.
Which planet is called morning star or evening star?
(a) Venus
(b) Mars
(c) Jupiter
(d) Mercury

Answer

Answer: (a) Venus

Class 8 Science Stars And Solar System MCQ Question 11.
Our galaxy is known as
(a) Earth galaxy
(b) Sun galaxy
(c) Milky Way
(d) Constellation

Answer

Answer: (c) Milky Way

Ch 17 Science Class 8 MCQ Question 12.
Which of the following is not a planet?
(a) Mercury
(b) Saturn
(c) Jupiter
(d) Great bear

Answer

Answer: (d) Great bear

Ncert Class 8 Science Chapter 17 MCQ Question 13.
Orion is a
(a) constellation
(b) star
(c) planet
(d) satellite

Answer

Answer: (a) constellation

Stars And Solar System Class 8 MCQ Online Test Question 14.
Shooting stars are called
(a) asteroids
(b) galaxies
(c) meteors
(d) andromeda

Answer

Answer: (c) meteors

Class 8 Ch 17 Science MCQ Question 15.
The planet farthest from the Sun is
(a) Uranus
(b) Neptune
(c) Saturn
(d) Mercury

Answer

Answer: (b) Neptune

MCQ Questions On Stars And Solar System Question 16.
If I am 13 years old, I have gone round the sun ___ times.
(a) Never gone round the sun
(b) 13
(c) 26
(d) Shall go round the sun when I shall be 15

Answer

Answer: (b) 13

Question 17.
The least dense planet is
(a) Earth
(b) Jupiter
(c) Saturn
(d) Uranus

Answer

Answer: (c) Saturn

Question 18.
____ appears as a bright head with a long tail. The tail grows in size as it approaches the sun.
(a) Asteroid
(b) Comet
(c) Planet
(d) Meteor

Answer

Answer: (b) Comet

Question 19.
During a clear night sky, bright light streaks are often visible. They are called shooting stars. They are actually
(a) Falling stars
(b) Comet
(c) Meteors
(d) Planet

Answer

Answer: (c) Meteors

Question 20.
_____ was the first Indian satellite.
(a) INSAT
(b) EDUSAT
(c) IRS
(d) Aryabhatta

Answer

Answer: (d) Aryabhatta

Question 21.
If Saturn is thrown into an ocean,
(a) It will float
(b) It will sink
(c) It will dissolve
(d) It will soak all water

Answer

Answer: (a) It will float

Question 22.
It is difficult to observe Mars because
(a) It is the smallest planet of this universe
(b) It is too far away from our planet
(c) It is hidden by the glare of the sun
(d) None of the above

Answer

Answer: (c) It is hidden by the glare of the sun

Question 23.
Ravi was looking for Venus in the sky at midnight. Mohan laughed at him because Venus
(a) Appears 1-3 hours after sunrise or 1-3 hours after sunset
(b) Appears 1-3 hours before sunrise or 1-3 hours after sunset
(c) Appears 1-3 hours before sunrise or 1-3 hours before sunset
(d) Appears 1-3 hours after sunrise or 1-3 hours before sunset

Answer

Answer: (b) Appears 1-3 hours before sunrise or 1-3 hours after sunset

Question 24.
Earlier we had 9 planets in our solar system of which one name has been eliminated as per IAU (2006). The planet is
(a) Uranus
(b) Neptune
(c) Pluto
(d) Earth

Answer

Answer: (c) Pluto

Question 25.
Light Year is
(a) Year full of light
(b) Year having light work
(c) Year which earth shall become lighter
(d) Distance travelled by light in 1 year

Answer

Answer: (d) Distance travelled by light in 1 year

Match the following items given in Column A with that in Column ‘B’:

Column A	Column B
(i) Nearest of the Sun	(a) Jupiter
(ii) Largest planet	(b) Star
(iii) Comets	(c) Artificial satellites
(iv) Alpha Centauri	(d) A constellation
(v) INSAT 3E	(e) Other than planets
(vi) Ursa major	(f) Neptune
(vii) Planet	(g) Mercury

Answer

Answer:

Column A	Column B
(i) Nearest of the Sun	(g) Mercury
(ii) Largest planet	(a) Jupiter
(iii) Comets	(e) Other than planets
(iv) Alpha Centauri	(b) Star
(v) INSAT 3E	(c) Artificial satellites
(vi) Ursa major	(d) A constellation
(vii) Planet	(f) Neptune

Fill in the blanks with the appropriate words:

1. ………….. are celestial bodies of the universe and continuously emit heat and light.

Answer

Answer: Stars

2. ………….. is the distance travelled by light in one year and is equal to 9.46 × 10¹² kilometres.

Answer

Answer: Light year

3. ………….. is the star which appears to be stationary near the northern horizon.

Answer

Answer: Pole Star

4. ………….. is a group of stars arranged in a definite pattern.

Answer

Answer: Constellation

5. ………….. are bright objects that revolve around the Sun.

Answer

Answer: Planets

6. ………….. constitutes Sun, eight planets with their moons and all other objects that are bound to the Sun due to gravity, e.g., asteroids, comets and meteors.

Answer

Answer: Solar system

7. ………….. are minor planets that revolve around the Sun and are located between Mars and Jupiter.

Answer

Answer: Asteroids

8. ………….. are very small sized bodies that revolve around the Sun in highly elliptical orbits and are characterized with a small head and a long tail.

Answer

Answer: Comets

9. ………….. are small stony or metallic bodies (meteors) travelling in interplanetary space that actually reach the Earth’s surface.

Answer

Answer: Meteorites

10. ………….. are the celestial bodies revolving around a planet.

Answer

Answer: Satellites

State whether the statements given below are True or False:

1. Sun is a star

Answer

Answer: True

2. Orion has 10 bright stars

Answer

Answer: False

3. Mercury has no satellite of its own

Answer

Answer: True

4. Planets do twinkle

Answer

Answer: False

5. Jupiter is the largest planet.

Answer

Answer: True

We hope the given NCERT MCQ Questions for Class 8 Science Chapter 17 Stars and the Solar System with Answers Pdf free download will help you. If you have any queries regarding Stars and the Solar System CBSE Class 8 Science MCQs Multiple Choice Questions with Answers, drop a comment below and we will get back to you soon.

Class 8 Science MCQ:

Our Environment Class 10 MCQ Online Test With Answers Questions

October 18, 2024

Class 10 Science Biology Chapter 15 MCQ With Answers

Biology Class 10 Chapter 15 MCQs On Our Environment

Our Environment Class 10 MCQ Question 1.
In the given food chain, suppose the amount of energy at the fourth trophic level is 5 kJ, what will be the energy available at the producer level?
Grass Grasshopper → Frog → Snake → Hawk
(a) 5 kJ
(b) 50 kJ
(c) 500 kJ
(d) 5000 kJ
Answer:

Class 10 Science Chapter 15 MCQ Question 2.
The Foodweb is constituted by:
(a) relationship between the organisms and the environment
(b) relationship between plants and animals
(c) various interlinked food chains in an ecosystem
(d) relationship between animals and the environment
Answer:

Our Environment Class 10 MCQ With Answers Question 3.
In an ecosystem, the 10% of energy available for transfer from one trophic level to the next is in the form of:
(a) heat energy
(b) light energy
(c) chemical energy
(d) mechanical energy
Answer:

Our Environment MCQ Class 10 Question 4.
Choose the incorrect statement from the following:
(a) Ozone is a molecule formed by three atoms of oxygen.
(b) Ozone shields the surface of the Earth from ultraviolet radiations.
(c) Ozone is deadly poisonous
(d) Ozone gets decomposed by UV radiations
Answer:

Ch 15 Science Class 10 MCQ Question 5.
Organisms of a higher trophic level which feed on several types of organisms belonging to a lower trophic level constitute the:
(a) food web
(b) ecological pyramid
(c) ecosystem
(d) food chain
Answer:
(a) food web

Explanation: Organisms of a higher trophic level feeding on several types of organisms belonging to a lower trophic level constitute the food web.

MCQ On Our Environment Class 10 Question 6.
Expand the abbreviation GAP:
(a) Governmental Agency for Pollution Control
(b) Gross Assimilation by Photosynthesis
(c) Ganga Action Plan
(d) Governmental Agency for Animal Protection
Answer:
(c) Ganga Action Plan

Explanation: GAP, 1985 came in existence to check water pollution in river Ganga.

Class 10 Our Environment MCQ Question 7.
Which of the following are biodegradable substances?
(a) Glass bottle, Grass
(b) Jutebag, polythene bag
(c) Cotton cloth, vegetable peels
(d) DDT, Pen refill
Answer:

MCQ Of Our Environment Class 10 Question 8.
Which of the statement is incorrect?
(a) Producers form the first prophic level.
(b) Produces trap solor energy and transform it into chemical energy in food.
(c) All plants are producers.
(d) Nutrients and energy enter the living world through producers.
Answer:

Class 10 Science Ch 15 MCQ Question 9.
Which of the following limits the number of trophic levels in a food chain?
(a) Decrease in energy at higher trophic levels
(b) Deficient food supply
(c) Polluted air
(d) Water
Answer:

Chapter 15 Class 10 Science MCQ Question 10.
In the given figure, the various trophic levels are shown in a pyramid. At which trophic level is maximum energy available?

(a) T4
(b) T2
(c) Ti
(d) T3
Answer:

Chapter 15 Science Class 10 MCQ Question 11.
Disposable plastic plates should not be used because:
(a) they are made of materials with light weight
(b) they are made of toxic materials
(c) they are made of biodegradable materials
(d) they are made of non-biodegradable materials
Answer:

Environment Class 10 MCQ Question 12.
Which one of the following stakeholders of forests causes the maximum damage to forest?
(a) People who live in or around the forest
(b) The forest department of the government
(c) The wildlife and native enthusiasts
(d) The industrialists
Answer:
(d) The industralists

Class 10 Chapter 15 MCQ Science Question 13.
Food web is constituted by:
(a) Relationship between the biotic and abiotic components of ecosystem.
(b) Relationship between abiotic compo-nents and recycling of nutrients.
(c) Relationship between biotic compo-nents and biogeochemical cycles.
(d) Various interlinked food chains in an ecosystem.
Answer:

Class 10 Science Chapter 15 MCQ Online Test Question 14.
Consider a terrestrial food chain: Grass Grasshopper → Frog → Snake → Eagle
The energy transfer in the above food chain will be from:
(I) Producer to decomposer
(II) Producer to primary consumer
(III) Primary consumer to secondary consumer
(IV) Tertiary consumer to Secondary consumer
(a) Both (I) and (III)
(b) Both (I) and (IV)
(c) Both (II) and (III)
(d) Both (III) and (IV)
Answer:

MCQ Of Chapter 15 Science Class 10 Question 15.
Which of the statements regarding food chain are correct?
(I) All food chains are of equal length and complexity.
(II) Food chains generally consist of only three or four steps.
(III) The greatest number of organisms in a food chain is of the producers.
(IV) Relationships between organisms can be shown only by straight lines.
(a) Both (I) and (II)
(b) Both (II) and (III)
(c) Both (III) and (IV)
(d) (II), (III) and (IV)
Answer:

Question 16.
Ozone-depleting substances are chiefly utilized in
(I) chimneys
(II) cooling and refrigeration applications and in the manufacturer of foam products
(III) all of the human activities
(IV) burning fossil fuels
(a) Only (I)
(b) Only (II)
(c) (I), (II) and (IV)
(d) (II), (III) and (IV)
Answer:

Question 17.
Consider the chemical reactions taking place at upper atmosphere:

Select the row containing the correct naming of A, B and C.
MCQ Questions for Class 10 Science Chapter 15 Our Environment with Answers 3
Answer:
(a) A: Molecular oxygen; B: Ultraviolet radiations; C: Ozone molecule

Explanation: Ozone at the higher levels of the atmosphere is a product of Ultraviolet radiation acting on oxygen (02) molecule. The higher energy UV radiations split apart some molecular oxygen (O2) into free oxygen (O) atoms and these atoms then combine with the molecular oxygen to form ozone as shown below:

Question 18.
The food habits of the organisms at the second and fourth trophic levels of a typical terrestrial are given in the table below.
Select the row containing the correct food habits:
MCQ Questions for Class 10 Science Chapter 15 Our Environment with Answers 5
Answer:

Question 19.
The protocol agreed upon in 1987 organized by the United Nations Environment Programme (UNEP) is related to:
(a) Food security
(b) Ozone layer depletion
(c) Global warming
(d) Sustainable deveLopment
Answer:
(b) Ozone Layer depletion

The protocol agreed upon in 1987 organized by the United Nations Environment Programme (UNEP) is related to:

Explanation: In 1987. the United Nations Environment Programme (UNEP) succeeded in forging an agreement to freeze CFC production at 1986 Levels in order to stop the depletion of ozone layer.

Question 20.
The formation of ozone in the stratosphere is powered by:
(a) UltravioLet radiation
(b) Infrared radiations
(c) Atmospheric oxygen
(d) CFC
Answer:

Question 21.
Which organism shown in the food chain above wouLd Contain the greatest concentration of chemical pollutants?
Phytoplankton → Krill → Small fish → Tuna → Shark
(a) Phytoplankton
(b) KriLl
(c) Tuna
(d) Shark

Assertion Reasoning questions Class 10 Science Chapter 15

For the following questions, two statements are given one labeled Assertion (A) and the other Labeled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given beLow:
(a) Both (A) and (R) true and (R) is correct explanation of the assertion
(b) Both (A) and (R) are true and (R) is correct Explanation of the assertion.
(c) (A) is true, but (R) is false.
(d) (A) is false, but (R) is true.

Question 22.
Assertion (A): Green plants of the ecosystem are the transducers.
Reason (R): Producers trap the radiant
energy of the sun and change it into chemical energy.
Answer:
(a) Both (A) and (R) are true and (R) is the correct explanation of assertion. Explanation: Green plants can make their own food. Hence, they are called producers. Since they capture the heat of the Sun to prepare their food, they are also called transducers. The plants prepare their food by trapping the energy of the Sun. They convert this light energy to chemical energy to form ATP molecules.

Question 23.
Assertion (A): Food chains generally consist of only three to four steps.
Reason (R): Autotrophs capture solar energy and convert it into chemical energy.
Answer:

Question 24.
Assertion (A): The maximum concentration of chemicals and pesticides occurs at the first trophic leveL
Reason (R): The chemicals and pesticides are not biodegradable.
Answer:

Question 25.
Assertion (A): Ozone shields the surface of the earth from ultraviolet radiation from the sun.
Reason (R): Ozone at the higher levels of the atmosphere is a product of UV radiations acting on oxygen molecules.
Answer:
(a) Both (A) and (R) are true and (R) is the correct explanation of assertion. Explanation: Ozone is formed when the high-energy UV radiations act on oxygen molecules (O₂) and split it into free oxygen atoms (O) which combine with the molecular oxygen to form ozone (O₃). Ozone thus shields the earth’s surface from the harmful effects of UV radiation.

Question 26.
Assertion (A): Improvements in our lifestyle have resulted in lesser amounts of waste material generation.
Reason (R): Changes in packaging have resulted in much of the waste generated being non-biodegradable.
Answer:
(d) (A) is false, but R is true.

Explanation: Improvements in our lifestyle have resulted in greater amounts of waste material generation due to changes in attitude and more and more things we use becoming disposable, which are also non-biodegradable.

Question 27.
Assertion (A): Frogs mostly occupy the second trophic level in food chains.
Reason: Frogs mostly feed on insects that depend on plants.
Answer:
(d) A is false, but R is true.

Explanation: Frogs mostly occupy the third trophic level in the food chain since they feed on insects which depend on plants and plants are the primary producers thus they occupy the first trophic level in the food chain. Thus A is false, but R is true.

Question 28.
Assertion(A): In the food chain third trophic level is occupied by Carnivores.
Reason(R): Some of the carnivores are secondary consumers.
Answer:

Question 29.
Assertion (A): Each step of the level of the food chain forms a trophic level.
Reason (R): The organisms occupying the first trophic levels are called autotrophs.
Answer:
(a) Both (A) and (R) are true, and (R) is the correct explanation of the assertion.

Question 30.
Assertion (A): Each step or level of the food chain forms a trophic leveL
Reason (R): The various components of the ecosystem are interdependent.
Answer:

Question 31.
Assertion (A): Polythene bags are non-biodegradable substances.
Reason (B): These bags cannot be broken down by microorganisms to simpler substances.
Answer:

Question 32.
Assertion (A): The food chains generally consist of only three or four steps.
Reason (B): Our food grains such as wheat and rice, vegetables and fruits and even meat contain varying amounts of pesticides.
Answer:
(b) Both (A) and (R) are true, but (R) is not the correct explanation of the assertion.

Explanation: The food chains generally consist of only three or four steps because after that the energy added to the biomass of each level is reduced and at the fourth trophic level it will be least. Thus Both A and R are true, but R is not the correct explanation of the assertion

Question 33.
Assertion (A): The amount of ozone in the atmosphere began to increase sharply in the 1980c.
Reason (R): The United Nations environment program (UNEP) succeeded in forging an agreement to freeze CFC production in 1987.
Answer:
(d) A is false, but R is true.

Explanation: The amount of ozone in the atmosphere began to decrease sharply in the 1980s because of the United Nations environment program (UNEP) succeeded in forging an agreement to freeze CFC production in 1987. Thus A is false, but R is true.

(Competency Based Questions (CBQs))

Question 1.
India today is facing the problem of overuse of resources, contamination of water and soil and lack of methods of processing the waste. The time has come for the world to say goodbye to “single-use plastics.” Steps must be undertaken to develop environment-friendly substitutes, effective plastic waste collection and methods of its disposal.

Indore treated 15 lakh metric tonnes of waste in just 3 years, through biomining and bioremediation techniques. Bioremediation involves introducing microbes into a landfill to naturally ‘break’ it down and biomining involves using trommel machines to sift through the waste to separate the ‘soil’ and the waste component.

The city managed to chip away 15 lakh metric tonnes of waste at a cost of around? 10 crore. A similar experiment was successfully carried out in Ahmedabad also.
(A) State two methods of effective plastic waste collection in your school.
Answer:

(B) Name any two uses of “single-use plastic” in daily Life.
Answer:
Uses of “Single-use plastic” in daily life.

In medical field: Plastic syringes, plastic gloves are made of single-use plastic and are used so that infection can be controlled.
Single-use plastic is also used in food industry for packing, straws, wrappers, spoons etc.
In emergency/ disaster situations where food and water has to be transported. Plastic will be light in weight and this packaging will be helpful to transport.

(D) Do you think microbes will work similarly in landfill sites as they work in the laboratory? Justify your answer.
Answer:
No, the microbes will not work similarly in landfill sites as they work in laboratory. Microbes need suitable conditions like temperature, moisture etc. and nutrients to grow. In laboratory we provide this atmosphere artificially to microbes for their growth but landfill sites do not have suitable atmosphere to grow.

Question 2.
Prerna visited a farm along with her family. Her younger brother was interested in knowing what kind of food is eaten by animals such as cows, buffaloes and deers. She told her brother that all these animals are herbivores as these eat only grass and plants.
MCQ Questions for Class 10 Science Chapter 15 Our Environment with Answers 6
How much of the net primary productivity of a terrestrial ecosystem is eaten and digested by herbivores?
(a) 100%
(b) 10%
(c) 1%
(d) 0.1%
Answer:
(b) 10%

Explanation: 10% of the net primary productivity of terrestrial ecosystem is eaten and digested by herbivores. According to 10% law, only 10% of the energy entering a particular trophic level of organisms is available for transfer to the next higher trophic level.

Question 3.
Human body is made up of five important components, of which water is the main component. Food, as well as potable water, are essential for every human being. The food is obtained from plants through agriculture. Pesticides are being used extensively for a high yield in the fields.

These pesticides are absorbed by the plants from the soil along with water and minerals and from the water bodies these pesticides are taken up by the aquatic animals and plants. As these chemicals are not biodegradable, they get accumulated progressively at each trophic level.

The maximum concentration of these chemicals gets accumulated in our bodies and greatly affects the health of our mind and body.
(A) Why is the maximum concentration of pesticides found in human beings?
Answer:
As human beings occupy the top level in any food chain, the maximum concentration of these chemicals get accumulated in our bodies due to biological magnification.

Explanation: Pesticides are being used extensively for a high yield in the fields. These pesticides mix up with soil and water. From soil and water, these pesticides are absorbed by the plants along with water and minerals. When herbivores eat this plant food, these chemicals pesticides go into their bodies through the food chain. When the next trophic level, carnivores eat herbivores, these pesticides get transferred to their bodies. As these chemicals are not biodegradable, they get accumulated progressively at each trophic level.

(B) Give on method which could be applied to reduce our intake of pesticides through food to some extent.
Answer:

We can reduce our intake of pesticides through food to some extent:
Wash fruits and vegetables before eating. Buy organic and locally grown fruits and vegetables.
Use non-toxic methods for controlling insects in the kitchen garden. (Anyone).

(D) With regard to various food chains operating in an ecosystem, man is a:
(a) Consumer
(b) Producer
(c) Producer and consumer
(d) Producer and decomposer
Answer:

Question 4.
Driving the Swach Bharat Abhiyaan forward, several NCOs are working towards the instaLLation of Blue and Green Dustbins for Municipal Corporations and schools in New Delhi. They are also carrying out a drive to educate children about the segregation of two different kinds of waste. The green is meant for wet waste and the blue one is for dry waste. This way they are separating biodegradable waste from non-biodegradable, thus providing various recycling and composting benefits and keeping the neighborhood clean and healthy.
MCQ Questions for Class 10 Science Chapter 15 Our Environment with Answers 7
In the following groups of materials, which group(s) contain(s) only non-biodegradable items?
(I) Wood, paper, leather
(II) Polythene, detergent, PVC
(III) Plastic, detergent, grass
(IV) Plastic, Bakelite, DDT
(a) (I)
(b) (II)
(c) (I) and (II)
(d) (II) and (IV)
Answer:

Question 5.
Series of organisms taking part at various biotic levels form a food chain. Each step or level of the food chain forms a trophic level. The autotrophs or the producers are at the first trophic level. They fix up the solar energy and make it available for heterotrophs or the consumers.
The herbivores or the primary consumers come at the second, small carnivores or the secondary consumers at the third and larger carnivores or the tertiary consumers form the fourth trophic level.
The interactions among various components of the environment involve flow of energy from one component of the system to another.
(A) What are trophic levels?
Answer:
Decomposers are microorganisms which breakdown complex organic substances into simple inorganic substances and help in recycling of nutrients. They feed on the dead and decaying bodies of plants and animals. They return the nutrients back to the soil and thus help in making this ecosystem stable e.g. fungi, bacteria.

(B) Give an example of a food chain.
Answer:

(D) Explain why the number of trophic levels in a food chain is limited?
Answer:
Only 10% of the energy gets transferred from one trophic level to the next. So after 3 or 4 trophic levels, the energy available for passing on is too less to support another trophic level. Very little usable energy remains after 4 trophic levels. Hence the number of trophic levels in a food chain is limited.

Question 6.
Nitya observed her grandmother making compost which she used to give to her plants. Composting is the natural process of recycling organic matter, such as leaves and food scraps, into a valuable fertilizer that can enrich soil and plants. Anything that grows decomposes eventually; composting simply speeds up the process by providing an ideal environment for bacteria, fungi, and other decomposing organisms (such as worms, sowbugs, and nematodes) to do their work. The resulting decomposed matter, which often ends up looking like fertile garden soil, is called compost. Fondly referred to by farmers as “black gold,” compost is rich in nutrients and can be used for gardening, horticulture, and agriculture.
MCQ Questions for Class 10 Science Chapter 15 Our Environment with Answers 8
The decomposers in an ecosystem:
(a) convert inorganic material to simpler forms
(b) convert organic material to inorganic forms
(c) convert inorganic material to organic compounds
(d) do not breakdown organic compounds
Answer:
(b) convert organic material to inorganic forms Explanation: The microorganisms, comprising bacteria and fungi, break down the dead remains and waste products of organisms. These microorganisms are the decomposers as they break down complex organic substances into simple inorganic substances that go into the soil and are once more used up by the plants.

Question 7.
You might have seen an aquarium, in the first activity, let us try to design an aquarium. What are the things that we need to keep in mind when we create an aquarium? The fish would need a free space for swimming (it could be a large jar), water, oxygen and food. We can provide oxygen through an oxygen pump (aerator) and fish food which is available in the market. If we add a few aquatic plants and animals it can become a self sustaining system.
In the second activity, while creating an aquarium did you take care not to put an aquatic animal which would eat others? Write the aquatic organisms in order of who eats whom and form a chain of at least three steps. A → B → C
(A) Identify the human-made ecosystems from the following:
(I) Ponds
(II) Crop fields
(III) Aquarium
(IV) Lakes
(a) Both (I) and (II)
(b) Both (II) and (III)
(c) (I), (III) and (IV)
(d) (II), (III) and (IV)
Answer:
(b) Both (II) and (III)

Explanation: Ponds and lakes are natural ecosystems, although there are some artificial or human made Lakes too. Aquariums and crop fields are human made ecosystems as these have been made by humans.

(B) The biotic and abiotic components in an aquarium are listed in the table below. Select the row containing the correct answer:

Biotic Components	Abiotic Components
(a) Aquatic plants and animals, water	Glass tank, aerator
(b) Glass tank, aquatic plants and animals	Water, aerator
(c) Aquatic plants and animals	Glass tank, water, aerator
(d) Glass tank, water, aerator	Aquatic plants and animals

(a) Ponds are natural ecosystems whereas aquariums are artificial ecosystems.
(b) There are less fishes in an aquarium as compared to a pond or lake
(c) The size of fishes is small in an aquarium as compared to a pond or lake
(d) Decomposers are absent in an aquarium whereas they are present in ponds or lakes.
Answer:

(D) What would have happened if we had put predator fishes in the aquarium?
(a) They would eat all the smaller fishes thereby generating lot of waste.
(b) They would eat away all the food available in the aquarium.
(c) They would compete with smaller fish for food and nutrition.
(d) They would not pose any problem in the aquarium.
Answer:

(E) Consider the following aquatic food chain consisting of three steps:

Identify the organisms at A, B and C:
(a) A: Zooplankton; B: Phytoplankton; C: Large fish
(b) A: Phytoplankton; B: Zooplankton; C: Small fish
(c) A: Zooplankton; B: Phytoplankton; C: Small fish
(d) A: Phytoplankton; B: Zooplankton; C: Large fish
Answer:

Question 8.
Ritu went to the shopping mall to buy some gifts for her parents on their wedding anniversary. She was pleasantly surprised to see that all shop owners were giving the items purchased in beautiful and coloured paper bags instead of plastic bags.
MCQ Questions for Class 10 Science Chapter 15 Our Environment with Answers 10
Why is it better to use paper bags than plastic bags?
Answer:
Paper is a biodegradable material, as it is obtained from wood whereas plastic is a non- biodegradable material. Therefore, paper is environment friendly whereas plastic causes environmental pollution.

Question 9.
In the first activity, find out what happens to the waste generated at home. Find out how the local body (panchayat, municipal corporation, resident welfare association) deals with the waste. Are there mechanisms in place to treat the biodegradable and nonbiodegradable wastes separately?
Calculate how much waste is generated at home in a day. How much of this waste is biodegradable? Suggest ways of dealing with this waste.
Next, find out how the sewage in your locality is treated. Are there mechanisms in place to ensure that local water bodies are not polluted by untreated sewage. Find out how the local industries in your locality treat their wastes.
(A) In the following groups of waste generated at home, which group contains only biodegradable items?
(a) Glass bottles, news paper, used tea leaves
(b) Polythene, detergent, Plastic packets
(c) Vegetable peels, paper, flowers
(d) Plastic packets, PVC, Glass bottles
Answer:
(c) Vegetable peels, paper, flowers

Explanation: Biodegradable substances are those substances which are easily degraded by natural processes by the action of microorganisms. All materials of plant and animal origin are biodegradable whereas man made substances such as plastic, detergents, PVC, glass, etc are non- biodegradable.

(B) Based on the study of how most local municipal authorities deal with the wastes generated at home, following statements are written. Select the incorrect statement.
(a) The waste generated at home are differentiated into biodegradable and non-biodegradable materials.
(b) All types of wastes are placed in a single bin.
(c) Most of the “dry-waste” is processed at waste-to-energy plants.
(d) Most of the “wet-waste” is sent for composting
Answer:

(C) Which of the following is not the correct practice of dealing with biodegradable wastes?
(a) Composting
(b) Anaerobic digestion of waste
(c) Landfills
(d) Burning
Answer:

(D) Select the correct statements regarding treatment of sewage in any locality:
(I) Sewage is treated at sewage treatment plants.
(II) Sewage treatment is the process of removing contaminants from industrial wastewater only.
(III) Physical, chemical, and biological processes are used to remove contaminants and produce treated wastewater.
(IV) Sewage is treatment is the process of removing contaminants from domestic and municipal wastewater.
(a) Both (I) and (II)
(b) Both (II) and (III)
(c) Both (III) and (IV)
(d) Both (I) and (IV)
Answer:

(E) The best practice followed by local industries in treating their wastes is:
(a) Source reduction and reuse
(b) Incineration
(c) Dumping solid wastes in open drain
(d) Dumping chemical wastes directly into water bodies
Answer:

Question 10.
Vijay’s science teacher was once sharing experiences about his village life. He explained how as a child, he would often hear the sound of frogs during nights and especially during the rainy days. But the situation has changed now with lesser population of frogs even in villages.
MCQ Questions for Class 10 Science Chapter 15 Our Environment with Answers 11
The number of malaria patients in a village increased tremendously when large number of frogs were exported from the village? What could be its cause?.
Answer:

Question 11.
The sun is the ultimate source of light and heat for planet Earth and sets in motion very large and complex systems that develop and sustain life. One such land-based ecosystem is the forest, supporting a biodiverse set of plants, which in turn provide food for other living things. Several distinct types of woodland habitats exist on Earth, such as conifer, deciduous and mixed. A study of the deciduous forest shows how a food chain functions within an ecosystem that experiences distinct seasonal changes.
MCQ Questions for Class 10 Science Chapter 15 Our Environment with Answers 12
(A) In an ecosystem, the main source of energy is
(a) heat released during transpiration
(b) solar energy
(c) heat released during respiration
(d) water
Answer:
(b) Solar energy

Explanation: Sun is the main source of energy for an ecosystem since green plants or producers are able to synthesize food only with the help of solar energy .

(B) Refer to the figure of food chain given above, identify A, B, C and D and select the correct combination of plots provided in the table below.
MCQ Questions for Class 10 Science Chapter 15 Our Environment with Answers 13
Answer:
(d) A: Producer; B: Primary Consumer; C: Secondary Consumer; D: Tertiary Consumer

Explanation: In all food chains, the green plants are the producers as they synthesize food by utilizing solar energy. The small insects marked !B’ or herbivores are the primary consumers as they feed on plants. Small animals marked ‘C’ are secondary consumers as they feed on small insects and similarly larger carnivores are tertiary consumers and marked ‘D‘ and ‘E’.

(C) Which of the following are functional components of an ecosystem?
(I) Decomposers
(II) Solar energy
(III) Energy flow
(IV)Air
(a) Both (I) and (II)
(b) Both (III) and (IV)
(C) (I), (II) and (IV)
(d) (I), (III) and (IV)
Answer:

(D) The correct identification of P and Q from the figure of food chain given is:
(a) P: Decomposers, Q: Nutrients
(b) P: Decomposers, Q: SoiL
(c) P: Producers, Q: Nutrients
(d) P Tertiary Consumers, Q: SoiL
Answer:

(E) The effect of completely removing ‘P’ from the food chain would be:
(a) Energy flow would be blocked
(b) Movement of minerals back to soil will be blocked
(c) Rate of decomposition would increase
(d) No carbon dioxide will be available for herbivores for respiration
Answer:
(b) Movement of minerals back to soil will be blocked

The effect of completely removing ‘P’ from the food chain would be:

Explanation: The organisms marked ‘P’ are the decomposers which help in cleansing our environment by feeding on dead and decaying organisms. They help in movement of minerals or nutrients back to the soil for the producers.

Question 12.
Sanket and his friends went to a nearby orchard to see how different fruits are cultivated. However, they observed that pesticides were being sprayed on the fruits without adhering to any guidelines.
MCQ Questions for Class 10 Science Chapter 15 Our Environment with Answers 14
How can excessive use of pesticides to protect the crops from diseases cause long-term damage to mankind?
Answer:
Pesticides are non-biodegradabLe chemicals which enter our food chain through the fruits we eat or are absorbed by the aquatic plants and animals. These concentration of these chemicals increases progressively at each trophic level and maximum concentration is found in human beings. This is known as biological magnification.

Question 13.
Ozone (O₃) is a gas which is present naturally within Earth’s atmosphere and is formed of three oxygen atoms. In the figure we see a standard profile of ozone gas concentration through the Earth’s atmosphere, extending from ground level up to 40 kilometres in altitude. Ozone plays a different role in atmospheric chemistry at different heights in the Earth’s atmosphere. We can differentiate this profile into two key zones:

Tropospheric ozone is that which is present in the lower atmosphere. Throughout most of the troposphere, ozone concentrations are relatively low (as shown in the diagram). Ground-level ozone can have negative impacts on human health and is therefore commonly referred to as ‘bad’ ozone.

Stratospheric ozone is that which is present in the upper atmosphere. As shown in the diagram, concentrations of ozone are higher in the stratosphere than in the troposphere.

The stratosphere includes the zone termed the ‘ozone layer’. In the ozone layer, it is often referred to as ‘good’ ozone since it plays a crucial role in absorbing potentially dangerous ultraviolet (UV-B) radiation from the sun.
MCQ Questions for Class 10 Science Chapter 15 Our Environment with Answers 15
(A) Study the above graph and select the row containing the correct information:

Good Ozone	Bad Ozone
Ionosphere	Mesosphere
Stratosphere	Ionosphere
Stratosphere	Troposphere
Mesosphere	Troposphere

Answer:
(c) Good ozone: Stratosphere; Bad ozone: Troposphere

(B) Ozone at higher atmosphere is a product of:
(a) Ultraviolet radiation acting on free oxygen.
(b) Infrared radiation acting on oxygen molecule.
(c) Infrared radiation acting on free oxygen.
(d) Ultraviolet radiation acting on oxygen molecule.
Answer:

(C) Select the incorrect statements regarding ozone gas:
(I) It is present only in troposphere.
(II) It is present in very small quantities in stratosphere.
(III) It can be beneficial or harmful, depending upon its location and concentration.
(IV) It shields the surface of the earth from ultraviolet (UV) radiation from the Sun.
(a) Both (I) and (II)
(b) Both (II) and (III)
(c) (I), (II) and (111)
(d) (II), (III) and (IV)
Answer:
(a) Both (I) and (II)

Explanation: Ozone is present in very low concentration in the lower atmosphere or troposphere, it is present in higher concentrations in the upper atmosphere or stratosphere. It is quite harmful when present in the lower atmosphere as it causes several diseases in humans. It is beneficial when present in upper atmosphere as it shields the surface of the earth from the harmful ultraviolet radiations of the sun.

(D) Which of the following products contain ozone-depleting substances?
(a) Motorbike, car with AC, Pesticides, Fire extinguisher
(b) Car with AC, refrigerator, fire extinguisher, aerosol sprays
(c) Motorbike, aerosol sprays, Pesticides, Fire extinguisher
(d) Heater, car with AC, Pesticides, Fire extinguisher
Answer:

(E) Which of the following is not the consequence of ozone layer depletion?
(a) Increased ultraviolet rays
(b) Malignant melanoma-Another form of skin cancer
(c) Cataracts and other eye damage
(d) Tides
Answer:

Question 14.
Monty was travelling to Delhi by road from Chandigarh. He observed a huge mountain like structure on GT Karnal road upon entering Delhi. He came to know that it was actually a landfill site and that Delhi has three landfill sites, viz. at Okhla, Bhalswa and Ghazipur. One can find waste burning at any give time in these landfills. They have also run out of space nearly a decade ago. Although the permissible limit for a garbage dumping is set to 20 meters, these sites have turned into huge mountains well beyond the permissible limit.
MCQ Questions for Class 10 Science Chapter 15 Our Environment with Answers 16
Suggest two measures to manage the garbage we produce.
Answer:
Two measures to manage the garbage we produce are listed below:
(1) Segregate the wastes and try to reuse as many items as possible.
(2) Put wet and dry wastes in separate garbage bins so that they can be easily recycled.

Question 15.
Toxic substances move up the food chain and become more concentrated at each level. These substances are often pollutants from industries or pesticides from farming. Consider any small fish that eats plankton that has been tainted with mercury. Hundreds of small fish might then contain just few parts of the mercury, not enough to cause major harm. A bird then might eat hundreds of the small fish. so that now instead of 200 ppm ¡n a single fish, that bird has much higher Levels of mercury. The toxin amplifies as it moves up the food chain. The amount of mercury is measured in ppm, which means parts per million.
MCQ Questions for Class 10 Science Chapter 15 Our Environment with Answers 17
(A) The phenomenon when concentrations of a harmful substance increases in organisms at higher trophic LeveLs in a food chain or food web is:
(a) Artificial eutrofication
(b) Biological accumulation
(c) Biological magnification
(d) Biological pollution
Answer:

(B) The table below gives the organism in a food web containing the Lowest and highest concentration of harmful chemical pollutants.
Select the row containing the correct answer.

Lowest Concentration	Highest Concentration
(a) Primary consumers	Secondary consumers
(b) Tertiary consumers	Producers
(c) Producers consumers	Secondary
(d) Producers consumers	Tertiary

Answer:
(d) Lowest Concentration: Producers Highest Concentration: Tertiary consumers

Explanation: The concentration of harmful chemical pollutants such as DDT and other pesticides increases progressively at each trophic level Therefore, tertiary consumers which occupy the highest trophic level will have the highest concentration and producers which occupy the Lowest trophic level will have the lowest concentration of harmful chemical pollutants.

(C) Which of the following statements are incorrect?
(I) Non-biodegradable wastes are biological in origin.
(II) Biodegradable wastes are degraded by microorganisms such as bacteria and fungi.
(III) Biodegradabte wastes enter the food chain and get biologically magnified.
(IV)Non-biodegradable wastes are absorbed by plants from the soil.
(a) Both (I) and (II)
(b) Both (I) and (III)
(c) Both (II) and (III)
(d) Both (III) and (IV)
Answer:
(b) Both (I) and (III)

Explanation: The biodegradable wastes are biological in origin whereas non-biodegradable wastes are plastic, metals etc. The non-biodegradable wastes enter the food chain and get biologically magnified as we higher up the food chain.

(D) It was observed that at places where DDT was used to control mosquitoes and other pests, the eggs of eagles would become fragiLe and break and the eagle almost became extinct. After DDT was banned by Lawmakers, eagle population has recovered.
The possible reason for this is:
(a) DDT is non-biodegradable and hence found in Largest concentration in tertiary consumers.
(b) DDT is non-biodegradable and found in Largest concentration in producers.
(c) Largest concentration of DDT is found in secondary consumers on which eagle feeds.
(d) DDT is a strong chemical which makes the eggs fragile.
Answer:

(E) Biological magnification is a result of
(a) climate change
(b) food shortages
(c) pollution
(d) extinction
Answer:

Question 16.
The chemical energy of food is the main source of energy required by all living organisms. This energy is transmitted to different trophic levels along the food chain. The energy flow in the ecosystem is one of the major factors that support the survival of such a great number of organisms. For almost all organisms on earth, the primary source of energy is solar energy.
MCQ Questions for Class 10 Science Chapter 15 Our Environment with Answers 18
(A) The flow of energy in an ecosystem is:
(a) Omnidirectional
(b) Unidirectional
(c) Bidirectional
(d) May be unidirectional or bidirectional
Answer:

(B) Non-biodegradable wastes enter the food chain through:
(I) Soil
(II) Water
(III) Air
(IV) Decomposers
(a) Both (I) and (II)
(b) Both (II) and (IV)
(c) Both (I) and (III)
(d) Both (III) and (IV)
Answer:
(a) Both (I) and (II)

Explanation: The non-biodegradable pesticides are either washed down into the soil or into the water bodies. From the soil, these are absorbed by the plants along with water and minerals, and from the water bodies these are taken up by aquatic plants and animals and hence enter the food chain.

(C) What happens to the solar energy incident on the autotrophs in a terrestrial ecosystem?
(a) It is completely captured and converted into food energy by the autotrophs.
(b) A part of it is reverted to the solar input
(c) A part of it is captured and passes to the herbivores.
(d) It moves progressively through the various trophic levels in both directions.
MCQ Questions for Class 10 Science Chapter 15 Our Environment with Answers 19
Answer:

(D) In the given food chain, suppose the amount of energy at fourth trophic level is 8 kJ.
Grass → Grasshopper → Frog → Snake → Hawk
Select the row containing the correct values of the energy available at the producer level and secondary consumer level?

Energy Available Producer Level	Energy Available at Secondary Consumer Level
(a) 800kJ	8kJ
(b) 800kJ	80kJ
(c) 8000kJ	72kJ
(d) 8000kJ	80kJ

Answer:

(E) If only 10% of the energy from one trophic level passes up to the next level, what happens to the 90% energy that is not passed on?
(a) It is lost as heat to the environment
(b) It is used in digestion of food and in doing work.
(c) It is used for growth and reproduction.
(d) All of the above
Answer:
(d) Energy Available at Producer Level: 8000 Id; Energy Available at secondary consumer level: 80 kJ

Explanation: According to 10 percent law, 90% of the energy captured from the previous trophic level is lost to the environment and only 10 percent is made available to the next trophic level.
in this food chain, at the 4th trophic level, 8 kJ energy is available to the snake. Therefore, we can calculate backwards to find energy available at the third, second and first trophic levels.

Energy available to Snake (Tertiary consumer) = 8 kJ = 10% of 80 kJ
Energy available to Frog (Secondary consumer) = 80 kJ = 10% of 800 kJ
Energy available to Grasshopper (Primary consumer) = 800 kJ = 10% of 8000 kJ.
The energy available to Grass (Producer) = 8000 kJ

Very Short Answer Type Questions

Question 1.
List two main components of an ecosystem.
Answer:
Two main components of an ecosystem are

Biotic component
Abiotic component

Question 2.
What is meant by ‘biological magnification’?
Answer:
Biological magnification is the process by which the harmful and toxic substances enter the food chain and get concentrated in the body of living organisms at each successive level in food chain.

Question 3.
Name any two man-made ecosystems.
Answer:
Examples of man-made ecosystems are aquarium, crop-fields, zoo, botanical garden, Greenhouse

Related Theory
An ecosystem is a self-sustained unit that comprises of all the interacting living things together with their non-living environment Manmade or artificial ecosystems that are carefully maintained in controlled environment.

Biodiversity in the man-made ecosystem will be very low as compared to natural ecosystem.

Question 4.
Why should biodegradable and non-biodegradable wastes be discarded in two different dustbins?
Answer:

Question 5.
What is meant by tropic level in a food chain? Construct a terrestrial food chain with four trophic levels. The energy flow in a food chain is always unidirectional. Why?
Answer:
Trophic level = Each step or level of the food chain forms a trophic level.

The ultimate source of energy used by living organisms is the sun.
Only 1% of solar radiations are captured by green plants in a terrestrial ecosystem and converted into food energy by photosynthesis. This energy is stored as chemical energy of food.
When green plants (producers) are eaten by primary consumers (Herbivores) a lot of heat is lost as heat to the environment and other activities. Only 10% of the food eaten is turned into its new body and is available for the next level of consumers (Primary carnivores).
Only 10% amount of organic matter reaches the next level of consumers (secondary carnivores).
Since, amount of available energy goes on decreasing at each trophic level, food chains usually consist of only 3 to 4 trophic levels. For example, grass receives 6000 J of energy from the sun. It will pass 10% of energy as per 10% law to grasshopper i.e. 600 J and so on.

MCQ Questions for Class 10 Science Chapter 15 Our Environment with Answers 20

Question 6.
What will be the amount of energy available to the organisms of the 2nd trophic level of a food chain, if the energy available at the first trophic level is 10,000 joules?
Answer:

Question 7.
Why do producers always occupy the first trophic level on every food chain?
Answer:

Question 8.
Give 2 examples of each:
(A) Organisms occupying the first trophic level
Answer:
Organisms occupying the first trophic level: trees, shrubs, grass.

Related Theory
Green plants make their own food by the process of photosynthesse. The food or energy is transferred from one organism to the other through food chain. So the srarting point of a food chain in produces i.e., plant occupy the first prophic level.

(B) Abiotic factors of an ecosystem
Answer:
Abiotic factors of an ecosystem: soil, water, Light.

Related Theory
All the ecolytems are made of the main components biotic and abiotic components. The biotic component (living organisms) interact continuously with abiotic component (non-living component).

Question 9.
What are the advantages of doth bags over plastic bags during shopping?
Answer:

MCQ Questions for Class 10 Science with Answers

Class 10 Science Biology MCQ:

MCQ Questions for Class 8 Science Chapter 18 Pollution of Air and Water with Answers

Pollution of Air and Water Class 8 MCQ Online Test With Answers Questions

October 18, 2024

Check the below Online Education NCERT MCQ Questions for Class 8 Science Chapter 18 Pollution of Air and Water with Answers Pdf free download. MCQ Questions for Class 8 Science with Answers were prepared based on the latest exam pattern. We have provided Pollution of Air and Water Class 8 Science MCQs Questions with Answers to help students understand the concept very well. https://ncertmcq.com/mcq-questions-for-class-8-science-with-answers/

You can refer to NCERT Solutions for Class 8 Science Chapter 18 Pollution of Air and Water to revise the concepts in the syllabus effectively and improve your chances of securing high marks in your board exams.

Class 8 Science Chapter 18 MCQ With Answers

Science Class 8 Chapter 18 MCQs On Pollution of Air and Water

Choose the correct option in the following questions:

Pollution Of Air And Water Class 8 MCQ Question 1.
Which gas is the major pollutant of air?
(a) Carbon monoxide
(b) Nitrogen
(c) Oxygen
(d) Propane

Answer

Answer: (a) Carbon monoxide

Class 8 Science Chapter 18 MCQ Question 2.
The increase in concentration of which gas is not responsible for Global Warming?
(a) Sulphur dioxide
(b) Nitrogen
(c) Carbon dioxide
(d) Methane

Answer

Answer: (b) Nitrogen

Class 8 Science Ch 18 MCQ Question 3.
In which year Ganga Action Plan was launched?
(a) 1980
(b) 1984
(c) 1982
(d) 1985

Answer

Answer: (d) 1985

MCQ On Pollution Of Air And Water Class 8 Question 4.
What radiations are absorbed by CO₂?
(a) Ultrared radiations
(b) Infrared radiations
(c) Ultraviolet radiations
(d) None of these

Answer

Answer: (b) Infrared radiations

Class 8 Pollution Of Air And Water MCQ Question 5.
Which element is present in the exhaust of automobiles?
(a) Lead
(b) Calcium
(c) Chromium
(d) Magnesium

Answer

Answer: (a) Lead

Pollution Of Air And Water MCQ Question 6.
The phenomenon of marble cancer is due to
(a) soil particles
(b) fog
(c) CFCs
(d) acid rain

Answer

Answer: (d) acid rain

MCQ Questions For Class 8 Science With Answers Pollution Of Air And Water Question 7.
The solid or liquid particles dispersed in the air are called
(a) oxides
(b) acids
(c) hydrocarbons
(d) aerosols

Answer

Answer: (d) aerosols

Class 8 Science Pollution Of Air And Water MCQ Question 8.
The type of pollution which is likely to affect Taj Mahal in Agra to a greater extent is
(a) air pollution
(b) soil pollution
(c) water pollution
(d) noise pollution

Answer

Answer: (a) air pollution

Pollution Of Air And Water Class 8 MCQs Question 9.
The major causes of air pollution include
(a) burning of coal and petroleum
(b) afforestation
(c) deforestation
(d) recycling of paper

Answer

Answer: (a) burning of coal and petroleum

Ch 18 Science Class 8 MCQ Question 10.
Bhopal tragedy was caused due to
(a) air pollution
(b) emission of poisonous gas
(c) water pollution
(d) leakage of poisonous gas

Answer

Answer: (d) leakage of poisonous gas

MCQ On Pollution Of Air And Water Pdf Question 11.
Which of the following contents is most harmful to aquatic animals?
(a) Heavy metal ions
(b) Sodium ions
(c) Potassium ions
(d) Chloride ions

Answer

Answer: (a) Heavy metal ions

MCQ Of Pollution Of Air And Water Class 8 Question 12.
Water containing high salt concentration can be purified by
(a) boiling
(b) UV irradiation
(c) filtration
(d) reverse osmosis

Answer

Answer: (d) reverse osmosis

Pollution Of Air Class 8 MCQ Question 13.
Which of the following is a non-biodegradable pollutant?
(a) Sulphur dioxide
(b) DDT
(c) Nitrogen oxide
(d) Hydrogen oxide

Answer

Answer: (b) DDT

Air And Water Pollution Class 8 MCQ Question 14.
Which of the following is major source of water pollution?
(a) Industrial wastes
(b) Untreated sewage
(c) Use of fertilisers
(d) Toxic metals

Answer

Answer: (b) Untreated sewage

MCQs On Pollution Of Air And Water Question 15.
Which of the following techniques of irrigation should be used to save water?
(a) Water wheel
(b) Canal irrigation
(c) Drip irrigation
(d) Lift irrigation

Answer

Answer: (c) Drip irrigation

Question 16.
Carbon monoxide in vehicle exhaust causes
(a) Increased oxygen carrying capacity of RBCs
(b) Reduced Nitrogen carrying capacity of RBCs
(c) Reduced oxygen carrying capacity of RBCs
(d) Reduced carbon carrying capacity of RBCs

Answer

Answer: (c) Reduced oxygen carrying capacity of RBCs

Question 17.
Smog =
(a) Smoke in dog’s stomach
(b) Smoke + fog
(c) Smoke dog
(d) frog in fog

Answer

Answer: (b) Smoke + fog

Question 18.
The gas used in refrigerating appliance causing serious damage to ozone is
(a) MFCs
(b) CFCs
(c) LPCs
(d) DPCs

Answer

Answer: (b) CFCs

Question 19.
Acid rain mainly contains
(a) Sodium chloride
(b) Sulphur dioxide and Nitrogen dioxide
(c) Hydrochloric acid
(d) Carbon tetra chloride

Answer

Answer: (b) Sulphur dioxide and Nitrogen dioxide

Question 20.
Marble cancer is caused by
(a) bacteria
(b) virus
(c) Acid rain
(d) Alkali rain

Answer

Answer: (c) Acid rain

Question 21.
Greenhouse effect is
(a) Painting house green in colour
(b) Wearing green colour dress
(c) Having green room in the house
(d) Sun’s heat is trapped and not allowed to escape

Answer

Answer: (d) Sun’s heat is trapped and not allowed to escape

Question 22.
Greenhouse gases includes
(a) CO₂, Methane, Nitrous oxide
(b) CO₂, Argon, Nitrous oxide
(c) CO₂, Methane, Chlorine
(d) CO₂, Methane, Flourine

Answer

Answer: (a) CO₂, Methane, Nitrous oxide

Question 23.
_____ is a commonly used chemical method for purifying water.
(a) Brominization
(b) Flourination
(c) Filtration
(d) Chlorination

Answer

Answer: (d) Chlorination

Question 24.
Ganga Action Plan is associated with
(a) Increase of fish culture in the Ganges
(b) Reduce Ganga water pollution
(c) Construct more bridges over the Ganges
(d) Increase water transport on the Ganges

Answer

Answer: (b) Reduce Ganga water pollution

Question 25.
Van Mahotsav is
(a) Planting trees in January
(b) Cutting trees in January
(c) Cutting trees in July
(d) Planting trees in July

Answer

Answer: (d) Planting trees in July

Match the following items given in Column ‘A’ with that in Column ‘B’:

Column A	Column B
(i) Greenhouse gas	(a) Absorbed by CO₂
(ii) Infrared radiations	(b) Polluting gas
(iii) Oxides which affect vegetation	(c) Fog
(iv) Sulphur dioxide	(d) Caused by smog
(v) Condensed wider vapour in air	(e) Smoke + fog + fumes
(vi) Asthma	(f) Carbon dioxide
(vii) Smog	(g) Nitrogen oxides

Answer

Answer:

Column A	Column B
(i) Greenhouse gas	(f) Carbon dioxide
(ii) Infrared radiations	(a) Absorbed by CO₂
(iii) Oxides which affect vegetation	(g) Nitrogen oxides
(iv) Sulphur dioxide	(b) Polluting gas
(v) Condensed wider vapour in air	(c) Fog
(vi) Asthma	(d) Caused by smog
(vii) Smog	(e) Smoke + fog + fumes

Fill in the blanks with the appropriate words:

1. Air contains the highest percentage of …………..

Answer

Answer: nitrogen

2. Most of the atmospheric air is contained in the atmospheric layer called …………..

Answer

Answer: troposphere

3. Stratosphere layer of the atmosphere protects us from …………..

Answer

Answer: ultraviolet radiations

4. An odd combination of smoke and fog is called ……………

Answer

Answer: smog

5. The solid or liquid particles dispersed in air are called ……………

Answer

Answer: aerosols

State whether the statements given below are True or False:

1. Carbon monoxide is a poisonous gas.

Answer

Answer: True

2. CFCs are not used in air conditioners.

Answer

Answer: False

3. Infrared radiations are absorbed by oxygen.

Answer

Answer: False

4. Ultra violets radiations are absorbed by ozone.

Answer

Answer: True

5. SO₂, CO₂and Nitrogen oxides are polluting gases.

Answer

Answer: True

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