Question

When a hydrogen atom emits a photon of energy 12.1 eV, its orbital angular momentum changes by 

(a) 1.05 x 10^-34 J s 

(b) 2.11 x 10^-34 J s 

(c) 3.16 x 10^-34 J s 

(d) 4.22 x 10^-34 J s

Answer 1

Correct Answer is:(b) 2.11 x 10^-34 J s 

Emission of a photon of 12.1 eV requires a transition from n = 3 to n = 1.

Change in orbital angular momentum = h/2π (3-1) = 4/π.