Nitrogen shows trivalency in its halides but phosphorus can form PCl3 as well as PCl5 - Chemistry -

Question

Nitrogen shows trivalency in its halides but phosphorus can form
PCl3 as well as PCl5

Brendon Mccullum · Answer

Due to lack of d orbitals nitrogen cannot expand it's covalency,
but the higher elements have d orbitals and therefore can expand
it's covalency and form pentahalides

Nitrogen shows trivalency in its halides but phosphorus can form PCl3 as well as PCl5.