Atoms and Molecules Class 9 MCQ Online Test With Answers Questions

Check the below Online Education NCERT MCQ Questions for Class 9 Science Chapter 3 Atoms and Molecules with Answers Pdf free download. MCQ Questions for Class 9 Science with Answers were prepared based on the latest exam pattern. We have Provided Atoms and Molecules 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 3 Atoms and Molecules 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 3 MCQ With Answers

Chemistry Class 9 Chapter 3 MCQs On Atoms and Molecules

Atoms And Molecules Class 9 MCQ Question 1.
The chemical symbol for nitrogen gas is
(a) Ni
(b) N₂
(c) N⁺
(d) N

Answer

Answer: (b) N₂

Atoms And Molecules Class 9 MCQ With Answers Question 2.
The chemical symbol for sodium is
(a) So
(b) Sd
(c) NA
(d) Na

Answer

Answer: (d) Na

Converting grams to moles is super easy if you use mass to moles calculator above.

Class 9 Science Chapter 3 MCQ Question 3.
Which of the following would weigh the highest?
(a) 0.2 mole of sucrose (C₁₂H₂₂O₁₁)
(b) 2 moles of CO₂
(c) 2 moles of CaCO₃
(d) 10 moles of H₂O

Answer

Answer: (c) 2 moles of CaCO₃

Class 9 Atoms And Molecules MCQ Question 4.
Which of the following has maximum number of atoms?
(a) 18 g of H₂O
(b) 18 g of O₂
(c) 18 g of CO₂
(d) 18 g of CO₄

Answer

Answer: (d) 18 g of CO₄

Atom And Molecules Class 9 MCQ Question 5.
Which of the following correctly represents 360 g of water?
(i) 2 moles of H₂O
(ii) 20 moles of water
(iii) 6.022 × 10²³ molecules of water
(iv) 1.2044 × 10²⁵ molecules of water
(a) (i)
(b) (i) and (iv)
(c) (ii) and (iii)
(d) (ii) and (iv)

Answer

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

Heat & Mass Transfer MCQ with detailed explanation for interview, entrance and competitive exams.

MCQ On Atoms And Molecules Class 9 Question 6.
3.42 g of sucrose are dissolved in 18 g of water in a beaker. The number of oxygen atoms in the solution are
(a) 6.68 × 10²³
(b) 6.09 × 10²²
(c) 6.022 × 10²³
(d) 6.022 × 10²³21

Answer

Answer: (a) 6.68 × 10²³

MCQ Of Atoms And Molecules Of Class 9 Question 7.
A change in the physical state can be brought about
(a) only when energy is given to the system
(b) only when energy is taken out from the system
(c) when energy is either given to, or taken out from the system
(d) without any energy change

Answer

Answer: (c) when energy is either given to, or taken out from the system

Class 9 Science Ch 3 MCQ Question 8.
The relative molecular mass of Na₂S₂O₃.5H₂O is
(a) 250 amu
(b) 250 g
(c) 248 amu
(d) 248 g

Answer

Answer: (c) 248 amu

MCQ Atoms And Molecules Class 9 Question 9.
Which of the following has maximum number of atom?
(a) 18 g H₂O
(b) 18 g of O₂
(c) 18 g of CO₂
(d) 18 g of CH₄

Answer

Answer: (d) 18 g of CH₄

Ch 3 Science Class 9 MCQ Question 10.
Percentage of calcium in calcium carbonate is
(a) 40
(b) 30
(c) 48
(d) 36

Answer

Answer: (a) 40

Atoms And Molecules MCQ Class 9 Question 11.
Which has maximum number of molecules?
(a) 1 g of CO₂
(b) 1 g of N₂
(c) 1 g of H₂
(d 1 g of CH₄

Answer

Answer: (c) 1 g of H₂

Class 9 Chemistry Chapter 3 MCQ Question 12.
What mass of carbon dioxide (CO₂) will contain 3.011 × 10²³ molecules?
(a) 11.0 g
(b) 22.0 g
(c) 4.4 g
(d) 44.0 g

Answer

Answer: (b) 22.0 g

Class 9 Chapter 3 Science MCQ Question 13.
The value of Avogadro’s constant is:
(a) 6.0 × 10²⁴
(b) 6.01 × 10²²
(c) 6.022 × 10²³
(d) 6.022 × 10^-23

Answer

Answer: (c) 6.022 × 10²³

Class 9 Science Chapter 3 MCQ With Answers Question 14.
How many times an atom of sulphur is heavier than an atom of carbon?
(a) 32 times
(b) 12 times
(c) 8/3 times
(d) 12/32 times

Answer

Answer: (c) 8/3 times

Chapter 3 Science Class 9 MCQ Question 15.
The number of oxygen atoms in 4.4 g of CO₂ is approx.
(a) 6 × 10²²
(b) 6
(c) 12 × 10²³
(d) 1.2 × 10²³

Answer

Answer: (d) 1.2 × 10²³

Question 16.
Which of the following represents 12 u?
(a) Mass of 1 hydrogen atom
(b) Mass of C-12 atom
(c) Mass of 0-16 atom
(d) 1/12th of mass of C-12 atom.

Answer

Answer: (d) 1/12th of mass of C-12 atom.

Question 17.
Which of the following would weigh the highest?
(a) 0.2 mole of sucrose (C₁₂H₂₂O₁₁)
(b) 2 moles of CO₂
(c) 2 moles of CaCO₃
(d) 10 moles of H₂O

Answer

Answer: (c) 2 moles of CaCO₃

Question 18.
The molecule having an atomicity of 4 is:
(a) Sulphate molecule
(b) Ozone molecule
(c) Phosphorus molecule
(d) Methane molecule

Answer

Answer: (c) Phosphorus molecule

Fill in the blanks

1. In a chemical reaction, the sum of the masses of the reactants and products remain unchanged. This is called ……………

Answer

Answer: Law of Conservation of Mass

2. A group of atoms carrying a fixed charge on them is called …………..

Answer

Answer: Polyatomic ion

3. The formula unit mass of Ca₃(PO₄)₂ is ……………

Answer

Answer: (3 × atomic mass of calcium) + (2 × atomic mass of phosphorus) + (8 × atomic mass of oxygen) = 310

4. Formula of sodium carbonate is ………….. and that of ammonium sulphate is ……………

Answer

Answer: Na₂CO₃ (NH₄)₂ SO₄

5. Elements are represented by symbols and molecules by …………….

Answer

Answer: Chemical formula

6. The combining power of an element is known as its …………….

Answer

Answer: Valency

7. An atom or a group of atoms which carries positive or negative charge is called an ……………..

Answer

Answer: ion

8. The volume occupied by one mole of a gas under standard conditions of temperature and pressure is called ……………..

Answer

Answer: molar volume

9. The number of atoms present in one molecule of the substance is called its ……………

Answer

Answer: atomicity

10. Atomicity of H₂SO₄ is …………….

Answer

Answer: 7

Match the following columns
1.

Column I	Column II
(a) 28 g of He	(i) 58.54
(b) 0.5 mole of O₂	(ii) 7 mol
(c) Molecular mass of common salt	(iii) 60 g
(d) 1.5 mole of Ca	(iv) 16 g

Answer

Answer:

Column I	Column II
(a) 28 g of He	(ii) 7 mol
(b) 0.5 mole of O₂	(iv) 16 g
(c) Molecular mass of common salt	(i) 58.54
(d) 1.5 mole of Ca	(iii) 60 g

Column I	Column II
(a) Sodium carbonate	(i) NaHCO₃
(b) Sodium bicarbonate	(ii) Na₃PO₄
(c) Sodium sulphate	(iii) Na₂CO₃
(d) Sodium phosphate	(iv) Na₂SO₄

Answer

Answer:

Column I	Column II
(a) Sodium carbonate	(iii) Na₂CO₃
(b) Sodium bicarbonate	(i) NaHCO₃
(c) Sodium sulphate	(iv) Na₂SO₄
(d) Sodium phosphate	(ii) Na₃PO₄

Column I	Column II
(a) Silver	(i) Na
(b) Sodium	(ii) Ag
(c) Gold	(iii) K
(d) Potassium	(iv) Au

Answer

Answer:

Column I	Column II
(a) Silver	(ii) Ag
(b) Sodium	(i) Na
(c) Gold	(iv) Au
(d) Potassium	(iii) K

Answer the questions in one word:

1. Smallest particle which cannot be divided into simpler parts.

Answer

2. Which experiment led to the discovery of the atomic nucleus?

Answer

Answer: Rutherford’s alpha particle scattering experiment

3. What is the mass of a proton and a neutron?

Answer

Answer: 1 amu

4. What do the species \(_{1}^{3}\)A and \(_{2}^{3}\)B represent?

Answer

Answer: Isobars

5. What is the formula of hydrogen carbonate?

Answer

Answer: HCO₃^–

6. What is the chemical formula of aluminium sulphate?

Answer

Answer: Al₂(SO₄)₃

7. What is the formula unit mass of CaCl₂?

Answer

Answer: 111 u

8. What is the mass of 5 moles H₂O?

Answer

Answer: 90 g

1. Complete the following crossword puzzle by using the name of the chemical elements. Use the data given in table mentioned below.

Answer

Answer:
Down:
2. Gold
3. Iron
5. Phosphorus
7. Hydrogen

Across:
1. Silver
4. Copper
6. Mercury
8. Lead

We hope the given NCERT MCQ Questions for Class 9 Science Chapter 3 Atoms and Molecules with Answers Pdf free download will help you. If you have any queries regarding Atoms and Molecules 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 Chemistry MCQ: