The wavelengths involved in the spectrum of deuterium are slightly different from that of hydrogen spectrum, because
size of the two nuclei are different
nuclear forces are different in the two cases
masses of the two nuclei are different
attraction between the electron and the nucleus is different in the two cases.
As we learnt in
Effect of nucleas motion on radius of atom -
- wherein
Radius of nth orbital with nucleus motion
Radius of nth orbital without nucleus motion
mass of electron
mass of nucleus
Masses of and are different. Hence the corresponding wavelengths are different.
Correct option is 3.
Option 1)
size of the two nuclei are different
This is an incorrect option.
Option 2)
nuclear forces are different in the two cases
This is an incorrect option.
Option 3)
masses of the two nuclei are different
This is the correct option.
Option 4)
attraction between the electron and the nucleus is different in the two cases.
This is an incorrect option.
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