Electronic Excitation: Absorbing and Re-emitting Photons

Click For Summary

Discussion Overview

The discussion revolves around the behavior of molecules or atoms in excited electronic states when they interact with photons, particularly focusing on the effects of absorbing additional photons of the same or different wavelengths. The scope includes theoretical considerations of electronic excitation, potential energy surfaces, and optical properties of excited states.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants inquire about the effects on a molecule or atom already in an excited state when it is hit by another photon, questioning the outcomes of absorbing photons of the same or different wavelengths.
  • One participant suggests that if a photon with the same energy as the one that caused excitation hits the atom, it could lead to a more energetic excited state, dissociation, or a de-excitation process, or it might do nothing.
  • Another participant raises the question of whether an excited molecule can be treated as if it were in the ground state, asking if it would have different optical properties or absorb photons in different regions of the spectrum.
  • Some participants discuss the complexity of molecules compared to atoms, noting that molecules can have intersecting potential energy surfaces (PESs), different isomers, or even dissociation, which may affect their behavior when interacting with photons.

Areas of Agreement / Disagreement

Participants express varying viewpoints on the behavior of excited states and their interaction with photons, indicating that multiple competing views remain without a consensus on the outcomes or implications of these interactions.

Contextual Notes

Participants mention the dependence on definitions and the complexity of molecular behavior, including the potential for intersecting PESs and the implications for optical properties, which remain unresolved.

AlKindi
Messages
19
Reaction score
0
What's happen when a molecule or an atom is already in an excited electronic state and is hit from another photon?

Example 1: my molecule absorbs a VIS photon (there's a time in which the molecule is an upper electronic state before the re-emission or etc. etc. process) what happen if another photon with the same wavelength hit it in the while?

Example 2: and if a photon of another wavelength (e.g. IR)?
 
Physics news on Phys.org


Well, what would happen if an object that had no excited states got "hit" by a photon? Answer: elastic scatter
 


AlKindi said:
What's happen when a molecule or an atom is already in an excited electronic state and is hit from another photon?

Example 1: my molecule absorbs a VIS photon (there's a time in which the molecule is an upper electronic state before the re-emission or etc. etc. process) what happen if another photon with the same wavelength hit it in the while?

Example 2: and if a photon of another wavelength (e.g. IR)?

you mean a photon of the same energy that already caused the atom to go to an excited state?
 


AlKindi said:
What's happen when a molecule or an atom is already in an excited electronic state and is hit from another photon?

Example 1: my molecule absorbs a VIS photon (there's a time in which the molecule is an upper electronic state before the re-emission or etc. etc. process) what happen if another photon with the same wavelength hit it in the while?

Example 2: and if a photon of another wavelength (e.g. IR)?

It could achieve a more energetic excited state, could dissociate, could follow a de-excitation process, could do nothing...
 


granpa said:
you mean a photon of the same energy that already caused the atom to go to an excited state?

Yes a photon that can normaly be absorb when the molecule/atom is in the ground state (the same wavelength or a another wavelength).
 
Last edited:


juanrga said:
It could achieve a more energetic excited state, could dissociate, could follow a de-excitation process, could do nothing...

Ok, I was asking to myself, if a molecule/atom in a excited state could be treat as the same molecule/atom in a ground state: can the first have different optical proprieties, be trasparent absorbs in other region etc. etc.
 


Bill_K said:
Well, what would happen if an object that had no excited states got "hit" by a photon? Answer: elastic scatter


Thanks. So you esclude all the other phenomena, don't you think that the molecule could however behave as a different molecule? Could the molecule absorbs other photons? The final question maybe is: could the molecule do many process in the same time? Thanks.
 


AlKindi said:
Ok, I was asking to myself, if a molecule/atom in a excited state could be treat as the same molecule/atom in a ground state: can the first have different optical proprieties, be trasparent absorbs in other region etc. etc.

As said it depends, atoms are simpler but for molecules you can find intersecting PESs, different isomers or even dissociation
 


juanrga said:
As said it depends, atoms are simpler but for molecules you can find intersecting PESs, different isomers or even dissociation

Ok, I will learn more about intersecting potential energy surface. Thanks.
 

Similar threads

  • · Replies 14 ·
Replies
14
Views
3K
  • · Replies 21 ·
Replies
21
Views
3K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 19 ·
Replies
19
Views
3K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 19 ·
Replies
19
Views
2K