Question

Orbital angular momentum of an electron in a particular subshell is $\sqrt{5} \frac{h}{\pi} .$ Then find the maximum number of electrons which may be present in this subshell.

Answer 1

Orbital angular momentum $=\sqrt{l(l+1)} \frac{h}{2 \pi}$
$\Rightarrow \sqrt{l(l+1)} \frac{h}{2 \pi}=\sqrt{5} \frac{h}{\pi}$
$\sqrt{l(l+1)}=2 \sqrt{5}=\sqrt{20}$
$\Rightarrow l=4 .$
Hence, maximum number of electrons in this subshell
$= 2(2 l+1)=18$.