An electron makes a transition from orbit `n = 4` to the orbit `n = 2` of a hydrogen atom. The wave number of the emitted radiations `(R =` Rydberg's constant) will be

Options

A. `(R )/(16)`
B. `(3R)/(16)`
C. `(5R)/(16)`
D. `(7R)/(16)`

Answer

B

Explanation

For the transition from n = 4 to n=2
`1/lamda = R [1/2^2 - 1/4^2 ] = R [1/4 - 1/16] = (3R)/(16)`