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October 16 Information
Quantum physics: what is the most photons an electron can release?
"An electron at rest" isn't really a well-defined concept, since by the
uncertainty principle an electron whose position is entirely certain would have an infinite uncertainty in momentum.
Indeed, in such a condition as atomic orbitals or molecular orbitals, I guess I would define "at rest" as "in the ground state," and electrons at their ground state energy/in their ground state wavefunction are not going to be emitting photons at all. They could be excited by various means, such as thermal or absorbing a photon, etc., and then undergo radiative relaxation to emit a photon... but that's not generally going to happen when just at the ground state. Even something like
Raman scattering still involves excitation to at least a virtual state, if not a discrete excited electronic state. --
OuroborosCobra (
talk)
22:11, 16 October 2023 (UTC)reply
An electron present in some system can emit a photon, constrained by
conservation of energy,
conservation of momentum,
conservation of angular momentum and the
Pauli exclusion principle. For an isolated electron, the first two can never be met simultaneously (except for a zero-energy photon), so an isolated electron cannot emit photons. An electron present in some system with an electromagnetic field can change its state to emit photons, until no transition releasing energy and satisfying the other constraints is available. In a hydrogen atom, an electron dropping down one energy level at a time, starting at infinity, could emit infinitely many photons, but the total energy of those photons will be limited to 13.6 eV. If you pump energy into the electron (or rather: system) by having it absorb photons, it can emit photons forever.
PiusImpavidus (
talk)
08:44, 17 October 2023 (UTC)reply
Welcome to the Wikipedia Science Reference Desk Archives
The page you are currently viewing is a
transcluded archive page. While you can leave answers for any questions shown below, please ask new questions on one of the
current reference desk pages.
October 16 Information
Quantum physics: what is the most photons an electron can release?
"An electron at rest" isn't really a well-defined concept, since by the
uncertainty principle an electron whose position is entirely certain would have an infinite uncertainty in momentum.
Indeed, in such a condition as atomic orbitals or molecular orbitals, I guess I would define "at rest" as "in the ground state," and electrons at their ground state energy/in their ground state wavefunction are not going to be emitting photons at all. They could be excited by various means, such as thermal or absorbing a photon, etc., and then undergo radiative relaxation to emit a photon... but that's not generally going to happen when just at the ground state. Even something like
Raman scattering still involves excitation to at least a virtual state, if not a discrete excited electronic state. --
OuroborosCobra (
talk)
22:11, 16 October 2023 (UTC)reply
An electron present in some system can emit a photon, constrained by
conservation of energy,
conservation of momentum,
conservation of angular momentum and the
Pauli exclusion principle. For an isolated electron, the first two can never be met simultaneously (except for a zero-energy photon), so an isolated electron cannot emit photons. An electron present in some system with an electromagnetic field can change its state to emit photons, until no transition releasing energy and satisfying the other constraints is available. In a hydrogen atom, an electron dropping down one energy level at a time, starting at infinity, could emit infinitely many photons, but the total energy of those photons will be limited to 13.6 eV. If you pump energy into the electron (or rather: system) by having it absorb photons, it can emit photons forever.
PiusImpavidus (
talk)
08:44, 17 October 2023 (UTC)reply