Question

What do you mean by:
(a) Molecule of an element
(b) Molecule of a compound, with examples

Answer 1

(a) Group of atoms of same element is known as molecule of that element.

Example: $H_2,O_2,N_2$ etc.

(b) Group of atoms of different element is called molecule of a compound.

Example: $C{H}_4,N{H}_3,C{O}_2$ etc.