Question

Why chromium and copper have irregular electronic configuration?

Answer 1

Maybe because their valency differs

Answer 2

hey mate here is your answer:-

Why chromium and copper have irregular electronic configuration?

ans:- chromium and copper have irregular electronic configuration because in last In these cases, a completely full or half full d sub-level is more stable than a partially filled d sub-level, so an electron from the 4s orbital is excited and rises to a 3d orbital.

A/q to aufbau rule it is more easier for copper and chromium to lose its one electron from 4s to 3d orbital

to regain its completle stability...

Hope it helps bro....