Energy level after photon absorbtion

[Johnahh]

Say a photon was absorbed by an electron at 1s in an oxygen atom but it only had enough energy to move it to another energy level that was already occupied such a 2s etc. What happens to this photon?

 

[mfb]

The photon does not get absorbed if there is no available unoccupied energy level for the electron.

 

[Johnahh]

so how does the electron know that the photon does not have enough energy to move it to a free orbital?

 

[mfb]

Quantum mechanics. If a process is impossible, it just does not happen.

 

[sardar]

When a photon is absorbed by an electron, it transfers its energy to the electron, causing it to move to a higher energy level. In the case described, the electron was initially at the 1s energy level and was moved to a higher energy level, such as 2s, which was already occupied by another electron.

In this scenario, the photon's energy is still transferred to the electron, but the electron is unable to occupy the same energy level as the other electron. This results in the electron being in an excited state, which is unstable. The electron will quickly release the excess energy in the form of another photon and return to a lower energy level, such as the 1s level. This process is known as emission or fluorescence.

Therefore, in this situation, the absorbed photon is essentially re-emitted in a different direction and with a different wavelength. This phenomenon is important in various fields of science, such as spectroscopy, where the emitted photons can provide valuable information about the energy levels and structure of atoms and molecules.