If a hydrogen atom emits a photon of energy 12.75 eV and returns to its ground state, change in its orbital angular momentum is
3h2π
2hπ
h2π
hπ
(1)
ΔE=13.6 1−1n2∴ 12.75 = 13.6 1−1n2 ⇒ n=4∴ ΔL=4.hπ−1.h2π=3h2π