When a hydrogen atom emits a photon of energy 12.09eV,it's orbit's angular momentum changes by (where h is Planck's constant) ?
Given that,
Emission of photon of 12.1eV corresponds to the transition from
n=3,n=1
Now, change in angular momentum
=(n2−n1)×h2π
=(3−1)×h2π
=hπ
Hence, this is the required solution