The rule that explain the reason for chromium to have `[Ar]3d^(5)``4s^(1)` configuration instead of `[Ar]3d^(4),4s^(2)` is

Options

A. Pauli's ecclusion priciple
B. Aufbau priciple
C. Hund's rule
D. Heisenburg's priciple

Answer

c

Explanation

Hund.s rules state that electrons do not pair up in the orbitals unless all the degenerated orbital have got one electron each to get stability.
Hence, to get more stability chromium has `[AR]3D^(5)4S^(1)` Configuration instead of `[Ar]3d^(4)4s^(2)`.