What Spectral Series Appear in the Absorption Spectrum of Ground State Hydrogen?

[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 continuous 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 absorption spectra with missing frequency lines with respect to which levels are excited.

 

[R0man]

To begin, let's define some key terms. Energy levels refer to the discrete levels of energy that an atom can possess. Spectra refers to the range of wavelengths or frequencies of electromagnetic radiation that an atom can emit or absorb. A continuous spectrum is a spectrum that contains all possible wavelengths or frequencies, whereas a discrete spectrum only contains specific values.

In this scenario, we have a volume of hydrogen gas where all the atoms are in the ground state, meaning they are in their lowest energy level. When radiation with a continuous spectrum is passed through this gas, the atoms will absorb some of the energy from the radiation and transition to higher energy levels. This results in an absorption spectrum, where certain wavelengths or frequencies of the radiation are absorbed by the hydrogen atoms.

Since the hydrogen atoms are all in the ground state, they can only absorb energy and transition to higher energy levels. This means that only absorption lines corresponding to transitions from the ground state to higher energy levels will be present in the resulting spectrum. These absorption lines will correspond to the different spectral series of hydrogen, such as the Lyman, Balmer, and Paschen series.

The Lyman series corresponds to transitions to the first energy level, the Balmer series to the second energy level, and the Paschen series to the third energy level. Therefore, in the resulting absorption spectrum, we would expect to see lines from all of these series, as the hydrogen atoms absorb energy and transition to these higher energy levels.

In summary, when radiation with a continuous spectrum is passed through a volume of hydrogen gas in the ground state, the resulting absorption spectrum will contain lines corresponding to transitions to higher energy levels, from all of the different spectral series of hydrogen.