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

Answer

`(E)/(c ).(1)/(m)=(13.6xx3e)/(4cm_(p))=3.25m//s`

Explanation

Energy of the first line in Lyman series
`E=13.6xx(1-(1)/(4))eV=10.2 eV`
Velocity of atoms `=(p)/(m)=(E)/(c ).(1)/(m)=(10.2xx1.6xx10^(-19))/(3xx10^(8)xx1.67xx10^(-24))m//s=3.25 m//s`