What happens when an electron emits a photon?

an electron emits a photon and falls from a higher energy level to a lower energy level.
an electron emits a photon and jumps from a lower energy level to a higher energy level.
an electron emits a photon and jumps from a middle energy level to the valence shell.
an electron emits a photon and stays at a higher energy level.

An electron emits a photon and falls from a higher energy level to a lower energy level.

Explanation:

A quantized form of electromagnetic radiation is called a photon.

Since the electromagnetic radiation has dual characteristics. The photons are the energy wave packets of the radiation.

When an electron is exposed to such radiation, it absorbs some of the energies of photons and goes to the excited state.

The excited state is only a temporary state. So, the electron releases some energy that comes to a lower energy level.

vapour or gas assuming atmospheriv pressure

wavelegth as in spectrum red oygbiv