Question

Though nitrogen exhibits $+5$ oxidation state, it does not form pentahalide. Give reason.

Answer 1

Valency of nitrogen

Atomic number of Nitrogen $\left(Z\right)=7$

Electronic Configuration: $1s^{2}2s^{2}2p^3$

Nitrogen with $n=2$, has $s\text{and}p$ orbitals only.

It does not have vacant $d$ orbitals to expand its covalence beyond four.

That is why it does not form pentahalide but show $+5$ oxidation state.

Final answer: Due to lack of vacant $d$ orbitals