The Balmer series in the hydrogen spectrum corresponds to the transition from ` n_(1)=2` to `n_(2)=3,4`........ This series lies in the visible region. Calculate the wave number of line associated with the transition in Balmer series when the electron moves to n=4 orbit.
`(R_(H)=109677cm^(-1))`

Explanation

`barv = 109677 (1/(n_1^2) - 1/(n_2^2)) cm^(-1)`
`= 109677 (1/(2^2) - 1/(4^2)) = 109677 (1/4 - 1/16)`
`= 109677 xx 3/16 = 20564.4 cm^(-1)`