Hydrogen atom in ground state is excited by a monochromatic radiation of `lambda = 975 Å`. Number of spectral lines in the resulting spectrum emitted will be

Options

A. 3
B. 2
C. 6
D. 10

Answer

C

Explanation

`E_n-E_1=hv`
`(-13.6)/n^2+13.6=(hc)/lambda`
`(-13.6)/n^2`=12.74-13.60
`13.6/n^2`=0.85 eV
`n^2=13.6/0.85`
`n^2`=16
n=4
Number of lines =`n(n_1)/2 =(4(4-1))/2=6`