Give reasons for the following:

(i) The size of a Cl^- ion is greater than the size of a Cl atom.

(ii) Argon atom is bigger than chlorine atom.

(iii) Chlorine is less reactive than fluorine.

(iv) Inert gases do not form ion.

Define the term 'ionisation potential'.

Ionisation Potential values depends on (a) atomic size (b) nuclear pull. Explain.

State the trends in ionisatioin energy:

(a) across the period,

(b) down the group.