The wave number of first line of Balmer series of H-atom is `15200cm^(-1)`. The wave number of first Balmer line of `Li^(2+)` ion is:

Options

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

Answer

D

Explanation

`lamda_(e)=h/(mv)=h/(mx)`
`lamda_(n)=h/(mv)=h/(1840mx)(m_(n)=1840m_(e))`
`lamda_(e)=lamda_(n)` or `h/(mx)=h/(1840mv)`
or `v=x//1840`