Question

Atomic number of sodium is $11$. Write down the four quantum numbers of the electron having highest energy.

Answer 1

The electronic configuration of sodium is:
$1s^2,2s^{2}2p^6,3s^1$
$3s$-electron has the highest energy. Its quantum numbers are:
$n=3,l=0,m=0,s=+\frac{1}{2}$ or $-\frac{1}{2}$.