The wavelength of the first Balmer line `Li^(2+)` ion is `136800 cm^(-1)` .The wavelength of the first line of Balmer series of hydrogen atom is` ("in" cm^(-1))`

Options

A. 68400
B. 15200
C. 76000
D. 30800

Answer

B

Explanation

Atomic number of `Li^(2+) `is `3`
`(1)/(lambda) = R_(H)Z^(2)[(1)/(n_(1)^(2)) - (1)/(n_(2)^(2))]`
`136800 = R_(H) xx 9 [(1)/(2^(2)) - (1)/(3^(2))]`
`R_(H) [(1)/(2^(2)) - (1)/(3^(2))]= (136800)/(9) = 15200`