Question

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
A. `15200 cm^(-1)`
B. `60800 cm^(-1)`
C. `76000 cm^(-1)`
D. `136800 cm^(-1)`

Answer 1

Correct Answer - D
`bar v_(H_2^theta)= R((1)/(n_(1)^(2)) - (1)/(n_(2)^(2))) = 15200 cm^(-1)`
`bar v_(Li^theta)= RZ^(2)((1)/(n_(1)^(2)) - (1)/(n_(2)^(2))) = 3^(2)15200 = 136800 cm^(-1)`