Question

Explain the following observation – The stability of +3 state increases down the group in group 15 of the periodic table.

Answer 1

+3 o.s stability inc down the group whereas +5 o.s stability dec.this is because of inert pair effect(inability of inner orbital electrons to participate in bonding due to poor shielding effect of outer d & f electrons).because of large size down the group outermost three np3 electrons can easily form bond or get removed but inner electrons np2 are strongly attracted by nucleus.so only +3 o.s is generally stable down the group.