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When electronic transitions(excited to ground) take place in a hydrogen atom, does the linear momentum of proton-electron system remain constant?

BioPhysicist
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1 Answers1

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You are not saying it in your question, but you are asking about electronic transitions of the atom, and I assume you are asking about excitation and relaxation of the atom/electron, and photon absorption and emission.

You can talk about two things here:

  1. photon absorption, you are basically asking whether an atom receives a recoil when it absorbs a photon, and the answer is yes, this is called radiation pressure. Radiation pressure is the pressure exerted upon a surface due to the exchange of momentum between the object and the EM field.

https://en.wikipedia.org/wiki/Radiation_pressure

This is how solar sails work.

https://en.wikipedia.org/wiki/Solar_sail

  1. photon emission, you are basically asking whether an atom receives a recoil when it emits a photon, and the answer is yes.

Does an atom recoil when photon radiate?