Question

Account for the following : Nitrogen does not form pentahalide.

Give reasons:Nitrogen does not form pentahalide. 

Answer 1

Group 15 elements form pentahalides when they have empty d-orbitals, which can be used for forming coordinate bonds. Since nitrogen does not have d-orbitals, it cannot form petahalides.

Answer 2

Nitrogen belongs to second period. Thus, it has only s- and p- orbitals available for bonding. Due to the absence of d-orbitals in nitrogen it cannot expand its covalency upto 5. It can have covalency maximum upto 4, like in the case of ammonium ion NH₄⁺ (by donating all the lone pair of electrons). Thus, nitrogen does not form pentahalides.