set 3 MCQ Questions & Answers Detailed Explanation

Question : 1

Dalton's atomic theory successfully explained

1. Law of conservation of mass
2. Law of constant composition
3. Law of radioactivity
4. Law of multiple proportions

a) (i), (iii) and (iv)

b) (ii), (iii) and (iv)

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

d) (i), (ii) and (iv)

Question : 2

Radioactivity is measured by

a) Geiger Counter

b) Seismometer

c) Hydrometer

d) Ammeter

Question : 3

The formation of SO₂ and SO₃ explain

a) the law of multiple proportions

b) the law of definite properties

c) the law of conservation of mass

d) Boyle’s law

Question : 4

In a chemical change the total weight of the reacting substances compared to total weight of products is

a) always less

b) always more

c) never the same

d) always the same

Question : 5

An oxide of nitrogen has molecular weight 30. What is the number of electrons in one molecule of the compound?

a) 22

b) 15

c) 14

d) 23

Question : 6

The number of electrons in an element with atomic number X and atomic mass Y will be

a) (Y – X)

b) (X + Y)

c) (X – Y)

d) X