Energy Levels and Spectra

[CollectiveRocker]

When radiation with a continuous spectrum is passed through a volume of hydrogen gas whose atomes are all in the ground state, which spectral series will be present in the resulting absorption spectrum? Where do i even start?

[santoshroy]

When radiation with a continous spectrum is shined through H2 in ground state the following will occur.

1.The rotational degrees of freedom of H---H will get excited.
2. The vibrational degrees of freedom of H----H will get excited.
3.The electronic levels will get excited.

Now depending on the frequency range of the incident radiation, one would get absorbtion spectra with missing frequency lines with respect to which levels are excited.