Chemistry - Atomic Structure Question with Solution | TestHub

${}_{13}\mathrm{Al}\to 1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^1$ (Ground state)

Here, the highest energy electron is 3 p -electron $\therefore$

orbital angular momentum $\left({\mathrm{L}}_{3\mathrm{P}-\text{ orbital }}\right)=\sqrt{1(1+1)}\left(\frac{\mathrm{h}}{2\pi }\right)=\frac{\mathrm{h}}{\sqrt{2}\pi }$