Electronic Excitation: Absorbing and Re-emitting Photons

[AlKindi]

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 wavelenght hit it in the while?

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

 

[Bill_K]

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

 

[granpa]

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 wavelenght hit it in the while?

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

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

 

[juanrga]

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 wavelenght hit it in the while?

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

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

 

[AlKindi]

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 wavelenght or a another wavelenght).

 

[AlKindi]

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.

 

[AlKindi]

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.

 

[juanrga]

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

 

[AlKindi]

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.