Question

What is the electronic configuration of chromium atom (Z = 24)? Give a reason for your answer.

Answer 1

Electronic configuration of Cr atom is $1s^2,2s^2{p}^6,3s^2{p}^6{d}^5,4s^1$. This is because an electronic configuration with half-filled and completely filled orbitals is more stable. ${}_{24}Cr$ has $3d$ orbitals half-filled which is more stable configuration than normally expected i.e., $3d^{4}4s^2$.