Question

Cr+3 config

Answer 1

[Ar]3d^3

Answer 2

Chromium (Cr) has atomic number 24. Its ground state electronic configuration is $[Ar]3d^54s^1$ due to the stability of a half-filled d-subshell. To form the $Cr^{+3}$ ion, three electrons are removed. Electrons are removed from the outermost shell first (4s), followed by the next inner shell (3d). One electron is removed from the 4s orbital: $[Ar]3d^54s^0$. Two more electrons are removed from the 3d orbital: $[Ar]3d^{5-2}4s^0 = [Ar]3d^34s^0$.