Question

The angular momentum of an electron in 4s orbital, 3p orbital and 4th orbit respectively are :

• A. 0, $\frac{1}{\sqrt{2}}$, $\frac{h}{\pi }$, $\frac{2h}{\pi }$
• B. $\frac{1}{\sqrt{2}}$, $\frac{h}{\pi }$, $\frac{2h}{\pi }$, 0
• C. 0, $\frac{\sqrt{2}h}{\pi }$, $\frac{4h}{\pi }$
• D. $\frac{\sqrt{2}h}{\pi }$, $\frac{4h}{\pi }$, 0

Answer 1

The correct option is A 0, $\frac{1}{\sqrt{2}}$, $\frac{h}{\pi }$, $\frac{2h}{\pi }$

As we know, angular momentum of an electron in any orbital $=\sqrt{l(l+1)}h/2\pi$
for s-orbital l=0 so
angular momentum of an electron in 4s orbital = 0
for p orbital, l=1 so
angular momentum of an electron in 3p orbital = $=\sqrt{1(1+1)}h/2\pi =h/\sqrt{2}\pi$
Also angular momentum of an electron in any orbit = $\frac{nh}{2\pi }$ so
angular momentum of an electron in 4th orbit =$4h/2\pi =2h/\pi$