The wave number of the first line of Balmer series of hydrogen is `15200 cm ^(-1)` The wave number of the first Balmer line of `Li^(2+)` ion is

Options

A. `15200 cm^(-1)`
B. `60800 cm^(-1)`
C. `76000 cm^(-1)`
D. `136,800 cm^(-1)`

Answer

D

Explanation

For atoms/ions `bar(v) = R[(1)/(n_(1)^(2))-(1)/(n_(2)^(2))] Z^(2)`
For `Li^(2+), bar(nu) = 15200 xx 3^(3) = 136, 800 cm^(-1)`