atomic structure molecules and nuclear chemistry - Category wise Question and Answer Practice Test with Solutions

Question : 21

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 : 22 [NDA]

What is the weight of one atom of Hydrogen in grams?

a) 6.62 × 10^–24

b) 1.66 × 10^–24

c) 6.023 × 10^–23

d) None of these

Question : 23

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 : 24 [UPPSC (GIC) 2010]

Radioactivity is measured by

a) Geiger Counter

b) Seismometer

c) Hydrometer

d) Ammeter

Question : 25

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