Electronic Excitation: Absorbing and Re-emitting Photons

In summary, when a molecule or an atom is already in an excited electronic state and is hit by another photon, it could achieve a more energetic excited state, dissociate, follow a de-excitation process, or do nothing. It could also behave differently and have different optical properties compared to when it is in a ground state. However, this depends on factors such as intersecting potential energy surfaces, different isomers, or dissociation.
  • #1
AlKindi
19
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 wavelenght hit it in the while?

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


Well, what would happen if an object that had no excited states got "hit" by a photon? Answer: elastic scatter
 
  • #3


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 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?
 
  • #4


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 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...
 
  • #5


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 wavelenght or a another wavelenght).
 
Last edited:
  • #6


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.
 
  • #7


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.
 
  • #8


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
 
  • #9


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.
 

1. What is electronic excitation?

Electronic excitation is the process in which an electron in an atom or molecule absorbs energy, typically in the form of photons, and jumps to a higher energy level. This causes the electron to become temporarily unstable and leads to the emission of light or heat as the electron returns to its original energy level.

2. What is the role of photons in electronic excitation?

Photons are the fundamental units of light and carry energy. When an electron absorbs a photon, it gains the energy needed to jump to a higher energy level and become electronically excited. Without photons, electronic excitation would not occur.

3. How does electronic excitation differ from other forms of excitation?

Electronic excitation specifically refers to the process in which an electron is excited to a higher energy level. Other forms of excitation, such as vibrational or rotational excitation, involve the movement or rotation of atoms or molecules rather than electrons.

4. What are the applications of electronic excitation?

Electronic excitation plays a crucial role in many scientific fields and technologies. It is particularly important in spectroscopy, which is used to study the energy levels and properties of atoms and molecules. Electronic excitation also has applications in the fields of electronics, photonics, and optoelectronics.

5. How does electronic excitation contribute to the color of objects?

The color of an object is determined by the wavelengths of light that are absorbed and reflected by its surface. When an object is electronically excited, it absorbs specific wavelengths of light and reflects others, giving it a particular color. This is why objects can appear different colors under different lighting conditions.

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