# What is the electronic configuration of atomic chromium, Z=24?

Well for the chromium atom, $Z = 24$, we gots........
$1 {s}^{2} 2 {s}^{2} 2 {p}^{6} 3 {s}^{2} 3 {p}^{6} 4 {s}^{1} 3 {d}^{5}$
This is an unusual config......and $\text{Hund's rule}$ of maximum multiplicity operates; half-filled electronic orbitals are somewhat stabilized. In 1st year chem, you probably would not have to know this......in 2nd year inorganic chem., you would have to know this.
Upon ionization, the $4 s$ and $3 d$ electrons are removed to give $C {r}^{2 +}$, $1 {s}^{2} 2 {s}^{2} 2 {p}^{6} 3 {s}^{2} 3 {p}^{6} 3 {d}^{4}$; $C {r}^{3 +}$, $1 {s}^{2} 2 {s}^{2} 2 {p}^{6} 3 {s}^{2} 3 {p}^{6} 3 {d}^{3}$.