The electronic configuration of sodium is

Solution: The atomic number of sodium is  Z = 11.

So, the electronic configuration sodium is

$\text{Sodium}\left(\text{Na}\right)\to 1{\text{s}}^{2}2{\text{s}}^{2}2{\text{p}}^{6}3{\text{s}}^1\left(\text{or}\right)\left[\text{Ne}\right]3{\text{s}}^1$

 Since Neon (Ne) with the atomic number Z = 10 is most stable.

Because, it has octet number of electrons in its valency shell.