An atom of an element has 13 electrons and mass number 27. The nucleus of this atom contains ____________ neutrons.

(a)

26

(b)

13

(c)

14

(d)

27

The relative atomic masses of many elements are not whole number because

(a)

they are not determined accurately

(b)

they exist as isotopes

(c)

due to impurities

(d)

atoms ionize

The atomicity of Chlorine is

(a)

1

(b)

4

(c)

8

(d)

2

The total number of electrons present in 16 g of methane gas is

(a)

96.352 x 10²³

(b)

48.176 x 10²³

(c)

6.023 x 10²³

(d)

30.11 x 10²³

What mass of hydrogen and oxygen will be produced on complete electrolysis of 18 g of water

(a)

2 g hydrogen and 32 g oxygen

(b)

2 g hydrogen and 16 g oxygen

(c)

4 g hydrogen and 32 g oxygen

(d)

4 g hydrogen and 14 g oxygen

What is a hetero atomic molecule? Give two examples

Give an example of homo triatomic molecule

State Avogadro's Hypothesis.

List any two differences between atom and molecules.

Give the salient features of “Modern atomic theory”.

Derive the relationship between Relative molecular mass and Vapour density.

Give the applications of Avogadro's hypothesis.

How will you determine the atomicity of gases using Avogadro's hypothesis?

Calculate the gram molecular mass of carbon dioxide (CO₂)

Calculate the number of moles in 81g of aluminum.

Calculate the number of molecules in 11g of CO₂