# What is the electronic configuration of sodium ion?

For sodium, $Z = 11$, i.e. $1 {s}^{2} 2 {s}^{2} 2 {p}^{6} 3 {s}^{1}$.
If the metal is IONIZED, we gets.....$1 {s}^{2} 2 {s}^{2} 2 {p}^{6}$, and this is a NEON core, which we could represent as ${\left\{1 {s}^{2} 2 {s}^{2} 2 {p}^{6}\right\}}^{+}$, or ${\left[N e\right]}^{+}$. And thus the ion has the electronic configuration of the LAST Noble Gas, i.e. neon....many metal ions share this configuration.....$M {g}^{2 +}$, $A {l}^{3 +}$....