Monochromatic radiation of specific wavelength is incident on H-atoms in ground state. H-atoms absorb energy and emit subsequently radiations of six different wavelength. Find wavelength of incident radiations:

Options

A. 9.75 nm
B. 50nm
C. 85.8nm
D. 97.25nm

Answer

D

Explanation

`(n(n-1))/(2) = 6, n = 4`
`n = 4 , E_(4) = - 0.85 eV`
`n = 1 , E_(1)= - 13.6eV`
`therefore Delta E = 12.75 eV`
`12.75 eV = (1240 eV - nm)/(lambda)`
`lambda = 97.75 eV`