Question

For N and P,+5 oxidation state is more stable than +3 oxidation state but for Bi +3 oxidation state is more stable than +5 explain why?

Answer 1

due to inert pair effect
Bi +3 is more stable then P (+5.)

Answer 2

Answer: This is due to the inert pair effect.

Explanation: Due the poor shielding effect of intervening d or f electrons ,the effective nuclear charge increases. This increased nuclear charge holds the ns electron of the heavier element strongly and the tendency of the heavier element becomes more and more restricted. So the lower oxidation state becomes more and more stable than the higher oxidarion state.