What is an Electron explain
The electron is a part of the atom. The electron is a negatively charged subatomic particle The electron can be either free (not attached to any atom), or bound to the nucleus of an atom.
In conductor current flows due to the movement of electron. In the fluorescence process, an atom is excited to a level several steps above its ground state by the absorption of a relatively high-energy UV photon. This is called atomic excitation.
Once it is excited, the atom can de-excite in several ways, one of which is to re-emit a photon of the same energy as excited it, a single step back to the ground state. This is called atomic de-excitation.
Watch this video to learn about electrons, excitation and de-excitation.