Mon December 31, 2012 By: Yatin Gupta

what is inert-pair effect?

Expert Reply
Mon December 31, 2012
Inert pair effect: 
The tendency of the outermost s electrons to remain non ionized or unshared in post-transition compounds is called inert pair effect. The term inert pair effect is often used to the increasing stability of oxidation states which is 2 less than the group valency for the heavier elements of groups especially 13, 14, 15 and 16.
 The inert pair effect explains why common ions of Pb are Pb4+and Pb2+, and not just Pb4+ as we might expect from the octet rule.
Ask the Expert