A stationary hydrogen atom emits photon corresponding to the first line of Lyman series. If R is the Rydberg constant and M is the mass of the atom, then the velocity acquired by the atom is

Options

A. `3/4 (Rh)/(M)`
B. `(Rh)/(4M )`
C. `(Rh )/(2M)`
D. `(Rh)/(M)`

Answer

A

Explanation

from conservation of momentum :
` MV = (h )/( lamda) = hR (1- (1)/( 4 )) implies V = (3)/(4) (hR )/( M)`