Question

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

Answer 1

Correct Answer - A
Energy provided to the ground state electron
`=(hc)/(lambda)=(6.6xx10^(-34)xx3xx10^(8))/(975xx10^(-10))=(6.6xx3)/(975)xx10^(-16)`
`=0.020xx10^(-16)=2xx10^(-18)J=(20xx10^(-19))/(1.6xx10^(-19))eV`
`=(20)/(1.6)=12.5eV`
It means the electron is jump to n=3 from n=1
The number of possible spectral lines from n=3 to n=1 is 3
`{:(i.e.,(n=3),rarr,(n=1)),(,(n=3),rarr,(n=2)),("and",(n=2),rarr,(n=1)):}`