Question

Nitrogen Ncl3ka nirman karti hai jabki phasphoras Pcl3 and Pcl5 ka

Answer 1

nitrogen has absence of d- orbital ,thus it cannot expand its covalency . its max. covalency is +4, while as phosphorus has d - orbital thus it can form both PCl3 as well as PCl5

Answer 2

Due to covalency...of nitrogen is only 4 but....covalancy of phosphorus is 3, 5 both