Question

In an electron transition inside a hydrogen atom, orbital angular momentum may change by ($h$= Planck constant)

• A. $h$
• B. $\frac{h}{\pi }$
• C. $\frac{h}{2\pi }$
• D. $\frac{h}{4\pi }$

Answer 1

Answer: (B), (C)

The correct options are
B $\frac{h}{\pi }$
C $\frac{h}{2\pi }$

Bohr restricted the number of orbits on the hydrogen atom by limiting the allowed values of the angular momentum of the electron. For particle moving in a circular orbit has an angular momentum equal to its mass (m) times the velocity (v) times the radius of the orbit (r). Bohr assumed that the angular momentum of the electron can take on only certain values, equal to an integer times Planck's constant (h) divided by 2$\pi$.
Hence, for an electron transition inside a hydrogen atom, the value of orbital angular momentum may change to $\frac{h}{\pi }$ e.g. for transition $n_1=1$ and $n_2=3$ as
$L=\frac{h}{2\pi }(3-1)$

$L=\frac{h}{\pi }$

Or orbital angular momentum may have values integral multiple of $\frac{h}{2\pi }$.