Master Class 9 Science – Atoms and Molecules with Our MCQ Mock Test!

Are you confident about the laws of chemical combination, atomic structure, and writing chemical formulas? Test your understanding with this MCQ-based mock test on Atoms and Molecules, designed specially for Class 9 students. This test covers all key concepts — from Dalton’s atomic theory and the law of conservation of mass to mole concept, atomic mass, molecular mass, and numerical problems based on these topics.

With well-curated multiple-choice questions following the latest CBSE syllabus, this mock test gives you a complete exam-like experience. It helps you strengthen your concepts, improve accuracy, and identify weak areas for focused revision. Perfect for both school exams and quick self-assessment!

Attempt now and see how strong your basics are in Atoms and Molecules!

1. How many atoms are present in 52 u of He ?

 
 
 
 

2. The mass of 18 ml of water (H2O) at 4° C is equal to

 
 
 
 

3. The balancing of chemical equation is based on

 
 
 
 

4. Identify the correct one from the following statements.

 
 
 
 

5. How many moles of electrons weigh equal to one kilogram? [Mass of 1 e = 9.1 × 10–31 kg]

 
 
 
 

6. 1.5 g of hydrocarbon on combustion in excess of oxygen produces 4.4 g of CO2 and 2.7 g of H2O, the data illustrates

 
 
 
 

7. NaOH (aq) + HNO3 (aq) → NaNO3 (aq) + H2O (l) In this reaction Nitric acid acts as

 
 
 
 

8. Identify the correct symbol of Gold.

 
 
 
 

9. If isotopic distribution of C-12 and C-14 are 98% and 2% respectively, then number of C-14 atoms in 12 g of carbon is

 
 
 
 

10. Arrange the following in increasing order of number of molecules.

I. 0.5 mol of H2
II. 4.0 g of H2
III. 18 g of H2O
IV. 2.2 g of CO2

 
 
 
 

11. Arrange the following in decreasing order of mass

I. 1023 molecules of H2

II. 0.1 mol of H2O

III. 0.01 mole of atoms of Nitrogen

IV. 2.24 L of O2 at STP

 
 
 
 

12. The formula of Ammonium phosphate is

 
 
 
 

13. 2 moles of H atoms at STP occupy volume of

 
 
 
 

14. 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

 
 
 
 

15. Which of the following contains maximum number of atoms ?

 
 
 
 

16. Which of the following illustrates the law of conservation of mass ?

 
 
 
 

17. The number of atoms present in 0.5 mol of nitrogen atoms is same as in

 
 
 
 

18. Out of 1.0 g oxygen gas, 1.0 g of oxygen atoms and 1.0 g of ozone, the maximum number of atoms are contained in

 
 
 
 

19. The mass of sodium in 5.85 g of NaCl is

 
 
 
 

20. The mass of magnesium oxide formed by burning 1.2 g of Mg in excess of oxygen is

 
 
 
 

21. Which pair of species contains same percentage of carbon?

 
 
 
 

22. Molecular weight of CuSO4. 5H2O is equal to [Cu = 63.5 u, S = 32 u, O = 16 u, H = 1 u]

 
 
 
 

23. If the density of water is 1 g cm–3, then the volume occupied by one molecule of water is approximately

 
 
 
 

24. An element has 8% of sulphur. What will be the minimum molecular weight of the compound ?

 
 
 
 

25. The combining capacity of an element is called

 
 
 
 

26. A sample of AlF3 contains 3.0 × 1024 F– ions. The number of formula units of this sample is

 
 
 
 

27. 18 g of water is electrolysed. The weight of oxygen formed will be

 
 
 
 

28. Which of the following is correct statement ?

 
 
 
 

29. Which of the following statements is not true about an atom?

 
 
 
 

30. Which is not represented by 1 mole of nitrogen gas ?

 
 
 
 

Question 1 of 30