Question

Why NCL 5 is not exist but PCL5 exist ?

Answer 1

Electronic configuration of

N = 1s2 2s2 2 P3

P = Ne 3s2 3p3 3d0

here we can see that N has no d orbital to accommodate more electron but P has empty d orbital which can form more bonds with Cl that's why NCl5 does not exist while Pcl5 does