Class 9 Science MCQ Chapter 3 Atoms and Molecules

Class 9 Science MCQ Chapter 3 Atoms and Molecules, Class 9 Science MCQ Question Answer, Class 9 Science Multiple Choice Question Answer to each chapter is provided in the list of SCERT Science Class 9 Objective Types Question Answer so that you can easily browse through different chapters and select needs one. Class 9 Science MCQ Chapter 3 Atoms and Molecules Question Answer can be of great value to excel in the examination.

SCERT Class 9 Science MCQ Chapter 3 Atoms and Molecules

SCERT Class 9 Science MCQ Chapter 3 Atoms and Molecules Notes covers all the exercise questions in SCERT Science Textbooks. The NCERT Class 9 Science MCQ Chapter 3 Atoms and Molecules provided here ensures a smooth and easy understanding of all the concepts. Understand the concepts behind every chapter and score well in the board exams.

Atoms and Molecules

Chapter – 3

Multiple Choice Questions & Answers

1. If 9g of water is decomposed, it is always obtained –

(a) 2 g of hydrogen and 7 g of oxygen 

(b) 1 g of hydrogen and 8 g of oxygen 

(c) 3g of hydrogen and 6 g of oxygen 

(d) 4 g of hydrogen and 5 g of oxygen 

Ans. (b) 1 g of hydrogen and 8 g of oxygen.

2. The value of 1 metre is –

(a) 10⁹ nm 

(b) 10⁸ nm

(c) 10¹⁰ nm 

(d) 10¹¹ nm

Ans.(a) 10⁹ nm.

3. Relative size of a ant is –

(a) 10⁻³ m.

(b) 10⁻⁴ m.

(c) 10⁻³ m. 

(d) 10⁻² m.

Ans. (d)  10⁻² m.

4. Symbol for Hydrogen as proposed by Dalton was –

Ans. (c)

5. The symbol of the element ‘cobalt’ is

(a) CO 

(b) Co

(c) CB 

(d) Cb

Ans. (b) Co.

6. If 7g of carbon monoxide (CO) is decomposed, it is always obtained – 

(a) 3g of carbon and 4g of oxygen. 

(b) 2g of carbon and 5g of oxygen. 

(c) 4g of carbon and 3g of oxygen. 

(d) 5g of carbon and 2g of oxygen.

Ans.(a) 3g of carbon and 4g of oxygen.

7. which of the following statement is correct?

(a) as the average mass of the atom as compared to ¹/₁₂ th the mass of one carbon – 12 atom.

(b) as the average mass of the atom,as compared to ¹/₁₂ th the mass of one carbon – 13 atom.

(c) as the average mass of the atom,as compared to ¹/₁₁ th the mass of one carbon-13 atom.

(d) as the average mass of the atom, as compared to 1⅒ th the mass of one carbon-12 atom.

Ans.(a) as the average mass of the atom as compared to ¹/₁₂ atom. th the mass of one carbon – 12 atom.

8. Which of the following is atomic mass unit of chlorine?

(a) 32.5 

(b) 33.5

(c) 34.5 

(d) 35.5

Ans. (d) 35.5.

9. Which of the following is monatomic element?

(a) Nitrogen 

(b) Hydrogen

(c) Helium 

(d) oxygen

Ans. (c) Helium.

10. Which of the following is diatomic element?

(a) Argon 

(b) Chlorine

(c) Phosphorus 

(d) Sulphur

Ans. (b) Chlorine.

11. Which of the following is Tetra-atomic element?

(a) Phosphorus 

(b) Chlorine

(c) Nitrogen 

(d) Oxygen

Ans. (a) Phosphorus.

12. Which of the following is tetra-atomic molecules?

(a) Oxygen 

(b) Ozone

(c) Hydrogen 

(d) Nitrogen

Ans. (b) Ozone.

13. What is the ratio of mass between carbon and oxygen in carbon dioxide?

(a) 3:8 

(b) 5:6

(c) 2:9 

(d) 7:4

Ans.(a) 3:8

14. What is the Symbol of polyatomic ions of Sulphate?

(a) So₂²– 

(b) So₃²–

(c) So₄²– 

(d) So₄²+

Ans. (c) So₄²-

15. What is the symbol of oxide ion? 

(a) 0²⁺ 

(b) 0³⁺

(c) O⁻ 

(d) 0²⁻

Ans. (d) 0²⁻