Question

The magnetic quantum number of the valence electron of sodium is:

• A. $2$
• B. $3$
• C. $1$
• D. $0$

Answer 1

The correct option is D $0$

Electronic configuration of $Na$ ( it has 11 electrons) is $1s^{2}2s^{2}2p^{6}3s^1$.

Here the valence electron is in $3s$ orbitals ( $3s^1$). So, the orbital is s - orbital. The $l$ value (Azimuthal quantum number) of this $s-$ orbital is 0, so the magnetic quantum number will zero i.e. $m$ value is 0.