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

(N/A) Nitrogen has the electronic configuration $1s^2 2s^2 2p^3$.
It has only $s$ and $p$ orbitals in its valence shell $(n=2)$.
It lacks $d$ orbitals in its valence shell,which prevents it from expanding its covalency beyond $4$.
Therefore,nitrogen cannot form pentahalides like $NF_5$.