Atoms Absorbing Light & Emitting Photons: The Gas Experiment

AI Thread Summary
When a gas is bombarded with light, its atoms typically absorb the light and transition to a higher energy state. The subsequent emission of photons does not necessarily match the energy level of the absorbed photon, as it can vary based on the gas's constituents and the wavelength of the light. For example, an absorbed photon can result in the emission of multiple photons with different energy levels. The specific spectrum of emitted radiation can be used to determine the gas's composition, as each atomic species has a unique spectral signature. This principle is fundamental in fields like astrophysics for identifying the composition of stars.
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If a gas is bombarded with light will the atoms absorb the light and emit photons of an equal energy level?
 
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radaballer said:
If a gas is bombarded with light will the atoms absorb the light and emit photons of an equal energy level?

It is more complicated and depends on the constituents of the gas. Typically when a photon is absorbed an atom or molecule will go to a higher energy state. What happens next depends on the material and the photon wavelength.
 
They don't have to emit photons of an equal energy level... I'm talking about photon absorption...
For a rough example, suppose you have three energy levels... E_{3} > E_{2} >E_{1}... if the absorbed photon has energy E= |E_{3}- E_{1}|, then you can have the production of 2 photons of energy \epsilon_{a}=|E_{3}- E_{2}| and \epsilon_{b}=|E_{2}-E_{1}|...
 
mathman said:
It is more complicated and depends on the constituents of the gas. Typically when a photon is absorbed an atom or molecule will go to a higher energy state. What happens next depends on the material and the photon wavelength.

Is there any particular way to determine the constituency of gas as it relates to the release of photons
 
radaballer said:
Is there any particular way to determine the constituency of gas as it relates to the release of photons

Yes. The spectrum of the emitted radiation. Each atomic species has its own spectrum. This is how we know what stars are made of, among other things.
 
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