Calculate the wavelength of the first line in the Balmer series of hydrogen spectrum.

Answer

A, B, D

Explanation

Balmer series `(1)/(lambda) = R [(1)/(2^(2)) - (1)/(n^(2))] ,n = 3,4,5……`when `n = 3` (first number of balmer series)
`(1)/(lambda) = 1.09678 xx 10^(7)((1)/(2^(2)) - (1)/(3^(2))) = 1.09678 xx 10^(7) xx (5)/(36)`
`:. Lambda = 6564 xx 10^(-10) m = 6564 Å`