Why is PCl5 an exception to the octet rule, while PCl3 is not?
Please explain

polar because its electronegativity is between 0.4-1.7. why is PCl5 an exception to the octet rule, while PCl3 isnt. it has more than 8 valence electrons and is satisfied PCl3 is not because it is satisfied with 8 valence electrons.

Explanation

atomic mass = 39

number of neutrons = 20

number of protons= 19

electronic configuration = 1s2 2s2 2p6 3s2 3p6 4s1

the number of electron in first shell = 2

number of electrons in n=3 shell = 8