Question

The correct ground state electronic configuration of chromium atom is

• A. $\left[Ar\right]3d^{5}4s^1$
• B. $\left[Ar\right]3d^4{s}^2$
• C. $\left[AR\right]3d^{6}4s^0$
• D. $\left[Ar\right]4d^{5}4s^1$

Answer 1

The correct option is A

$\left[Ar\right]3d^{5}4s^1$

3d subshell filled with 5 electrons (half-filled) is more stable than that filled with 4 electrons. 1, 4s electrons jumps into 3d subshell for more sability.