Electron Excitation and Photon Emission: Understanding the Ground State

Click For Summary

Discussion Overview

The discussion revolves around the behavior of electrons in excited states, particularly focusing on photon absorption and emission. Participants explore the conditions under which an electron can emit a photon of higher energy than the one it absorbed, and the implications of not returning to the ground state.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant questions whether a photon of higher wavelength can be emitted after an electron absorbs a photon and enters an excited state.
  • Another participant clarifies the terminology, suggesting that "higher wavelength" should be referred to as "longer wavelength" and discusses the relationship between wavelength and energy.
  • It is proposed that an electron can emit a photon of higher frequency than it absorbed when transitioning to a lower energy state, provided it follows the selection rules.
  • Concerns are raised about the energy dynamics, specifically how an electron can emit a higher energy photon than it absorbed, with some suggesting that the extra energy comes from the electron's initial state above the ground state.
  • Participants confirm that a photon can be emitted from an excited state to any lower state, not necessarily the ground state.

Areas of Agreement / Disagreement

Participants generally agree that an electron can emit a photon when transitioning to a lower energy state, but there is some disagreement regarding the implications of wavelength and energy relationships, as well as the conditions under which this occurs.

Contextual Notes

There are unresolved questions regarding the definitions of wavelength and frequency, as well as the specific selection rules that apply to photon emission in this context.

MathewsMD
Messages
430
Reaction score
7
Just curious: if an electron absorbs a photon of energy, it is in an excited state. The electron may go to a lower energy state (but NOT the ground state). Can a photon (of higher wavelength than absorbed) be emitted still?

I don't quite see the importance of the electron having to go to the ground state in this case...
 
Physics news on Phys.org
Do you mean a longer wavelength, or a higher frequency? A "higher wavelength" doesn't make sense.

In any case, an electron can exist above the ground state, absorb a photon, and then fall to a lower state than what it was occupying emitting a photon of higher frequency than what it absorbed in the process.
 
Drakkith said:
Do you mean a longer wavelength, or a higher frequency? A "higher wavelength" doesn't make sense.

In any case, an electron can exist above the ground state, absorb a photon, and then fall to a lower state than what it was occupying emitting a photon of higher frequency than what it absorbed in the process.

Isn't a higher wavelength proportional to lower energy? How would it emit a higher energy photon (i.e. higher frequency) than what it absorbed?

So to confirm, a photon can still be emitted despite the electron not decaying to its ground state, just any state lower than its excited state, correct?
 
A photon can be emitted if the system goes from a higher energy state to a lower energy state (not necessarily the ground state), and if it abides by the selection rule.

Example: the Balmer lines in H atom.

Zz.
 
Last edited:
MathewsMD said:
Isn't a higher wavelength proportional to lower energy? How would it emit a higher energy photon (i.e. higher frequency) than what it absorbed?

The extra energy required to emit a photon of higher frequency than the electron absorbs comes from the extra energy it already had by being in a state above the ground state.

So to confirm, a photon can still be emitted despite the electron not decaying to its ground state, just any state lower than its excited state, correct?

Absolutely.
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 6 ·
Replies
6
Views
2K
Replies
4
Views
2K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 21 ·
Replies
21
Views
3K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 18 ·
Replies
18
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K