Differentiate between an ‘atom’ and a ‘molecule’.

ANSWER:

ATOM:

1. “Atom is the smallest particle of an element which can take part in chemical reactions.”
2. Atom may or may not exist independently.
3. Examples: H, O, N, Na etc.

MOLECULE:

1. “Molecule is the smallest particle of a substance which can exist independently.”
2. Molecule can exist independently.
3. Examples: He, H₂, H₂O, CO₂ etc.

(Ref. An Insight Into Objective Chemsitry-11, Ch-01, Q. No. 06)