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Jason Ko
- 16
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I'm recently studying Bohr's model. My textbook claims that only low-pressure gases emit a line spectrum while solids, liquids and high-pressure gases emit light with a continuous range but why?
How exactly does the change of energy level result in a continuous spectrum? Could you please explain it in detail?mfb said:Nearby atoms influence the energy levels in atoms, lowering or raising them a bit. In a low pressure gas this can be negligible, in solids and liquids it's very important.
The Pauli Exclusion Principle says that no two atoms can have precisely the same quantum levels and we never look at just one atom. The precise energy level of a system will be affected by more than the 'simple' fields that the theory suggests for a single atom; nearby atoms affect each other and the more and the closer they are means a (albeit narrow) range of energy states exists and lines 'broaden'.Jason Ko said:only low-pressure gases emit a line spectrum
And there I was, thinking that the Pauli Exclusion Principle dictated that no two electrons (generally fermions), within a quantum system (one atom), could share the same quantum state at the same time.sophiecentaur said:The Pauli Exclusion Principle says that no two atoms can have precisely the same quantum levels and we never look at just one atom.
The point is (imo) that there are more "quantum systems" than just single atoms. As soon as two atoms get within range of each other you have a quantum system. We were told about Pauli in the simple context of the Hydrogen atom and that system can be described by just four quantum numbers. Bring two or more atoms near each other and the total number of quantum numbers needed to describe the system 'fully' increases as the potential energy between them becomes significant. Molecular Hydrogen has a much more complicated spectral line structure.Baluncore said:And there I was, thinking that the Pauli Exclusion Principle dictated that no two electrons (generally fermions), within a quantum system (one atom), could share the same quantum state at the same time.
Just cos you can't see it, doesn't mean it's not happening. Glass is a transparent solid and you can see photons released inside it.Baluncore said:Photons emitted by a solid, or by a dense gas or plasma, do not tend to escape to be seen
Low-pressure gases emit a line spectrum because they have a lower density, which allows for the atoms to move around more freely. This movement results in the emission of specific wavelengths of light, creating a line spectrum.
The line spectrum in low-pressure gases is significant because it provides information about the energy levels and transitions of the atoms within the gas. This can help scientists identify the elements present in the gas and study their properties.
Yes, high-pressure gases can also emit a line spectrum. However, the spectrum may be less distinct due to the increased collisions between atoms, which can broaden the lines and make them less defined.
The pressure of a gas can affect its line spectrum by changing the density of the gas. A lower pressure results in a lower density and more distinct lines in the spectrum, while a higher pressure can lead to broadened and less defined lines.
Besides pressure, the temperature, composition, and energy levels of the gas can also affect its line spectrum. Additionally, the presence of external forces such as electric or magnetic fields can alter the spectrum as well.