Question

What do you understand by (a) inert pair effect (b) allotropy and (c) catenation?

Answer 1

(a) Inert pair effect:
On moving down the group, the tendency of s electrons to participate in chemical bonding decreases. This effect is called inert pair effect. Due to this, in group 13, the stability of +3 oxidation state decreases and the stability of +1 oxidation state increases.
(b) Allotropy:
Allotropy is the phenomenon in which an element exist in more than one form having same chemical properties by different physical properties. For example, diamond, graphite and fullerenes are allotropes of carbon.
(c) Catenation:
Atoms of carbon and some other elements link with one another through strong covalent bonds to form long chains or branches. This is called catenation. Usually, it is shown by C, S and Si.