The longest wavelength transitoin in one of the spectral series of hydrogen atom is 6563 Å. Identify the series to which the spectral line belongs.

Explanation

`(1)/(lamda)=R_(H)((1)/(n_(1)^(2))-(1)/(n_(2)^(2)))`
`therefore (1)/(n_(1)^(2))-(1)/(n_(2)^(2))=(1)/(lamdaR_(H))=(1)/(6563xx10^(-8)xx109678)=0.139`
Thus, n_(1)=2 and n_(2)=3`, indicating that the spectral line belongs to Balmer series.