An electrons of a stationary hydrogen aton passes form the fifth enegry level to the ground level. The velocity that the atom acquired as a result of photon emission will be
`(m` is the mass of the electron, `R`, Rydberg constanrt and `h`, Planck's constant)

Options

A. 24 hR/25m
B. 25hR/24m
C. 25m/24hR
D. 24m/25hR

Answer

A

Explanation

`(1)/(lamda) = R ((1)/(n_(1)^(2))- (1)/(n_(2)^(2)))`
`rArr (1)/(lamda) = R ((1)/(1^(2)) - (1)/(5^(2))) rArr (1)/(lamda)= (24R)/(25)`
Since, `lamda = (h)/(P)` [P= momentum]
`rArr P= mv= (h)/(lamda) rArr v= (24 hR)/(25m)`