Absorption Spectrum and Temperature

[Quelsita]

I'm going through some notes and came upon a question...

So, the absorption sepctrum can be seen when a gas sample is placed in the path of white incandescent light where the light absorbes descrete wavelengths.

I read that only some of these absorption lines appear if the gas is cool, but if the gas is hot, additional lines will appear.

My question is how to explain why the quantity of absorption lines visible is dependent upon the initial temperature of the gas sample?
I would say this has something to do with the energy of the atoms at high and low temps. but this would indicate the length of the wavelengths present, not the amount. Correct?

Any advice is appreciated.

 

[Aaron Barnard]

Yes, the energy of the atoms at high and low temperatures does affect the wavelength of light absorbed. However, the temperature of the gas sample also affects the number of atoms that are in excited states and therefore are able to absorb light. At lower temperatures, fewer atoms are in excited states and therefore fewer absorption lines are visible. At higher temperatures, more atoms are in excited states and therefore more absorption lines are visible.

 

[astrokreng]

The quantity of absorption lines visible in an absorption spectrum is indeed dependent on the initial temperature of the gas sample. This is because temperature affects the energy of the atoms in the gas, which in turn affects the wavelengths of light that are absorbed by the gas.

At lower temperatures, the atoms in the gas have lower energy levels and are only able to absorb certain wavelengths of light. This results in a limited number of absorption lines being visible in the spectrum. However, as the temperature of the gas increases, the atoms gain more energy and are able to absorb a wider range of wavelengths. This leads to the appearance of additional absorption lines in the spectrum.

To explain this further, we can look at the principles of quantum mechanics. Atoms have discrete energy levels, and when they absorb light, they can only do so at specific wavelengths that correspond to the energy difference between these levels. At lower temperatures, the atoms have lower energy levels and can only absorb certain wavelengths. But as the temperature increases, the atoms gain more energy and can occupy higher energy levels, allowing them to absorb a wider range of wavelengths.

In summary, the quantity of absorption lines visible in an absorption spectrum is dependent on the initial temperature of the gas sample because temperature affects the energy of the atoms in the gas, which in turn affects the range of wavelengths that can be absorbed.