Question

Excited H atom emits a photon of energy $12.1 \, eV$, orbital angular momentum of electron changes by

• A. $\frac{3h}{2 \pi}$
• B. $\frac{2h}{\pi}$
• C. $\frac{h}{\pi}$
• D. $\frac{3h}{ \pi}$

Answer 1

Answer: (C)

$\frac{h}{\pi}$

Answer 2

Emission of a photon of $12.1 \, eV$ requires a transition from $n = 3$ to $n = 1$.
Change in orbital angular momentum
$= \frac{h}{2 \pi } (3 - 1) = \frac{h}{\pi}$