When the electrons fall back down and leave the excited state, energy is re-emitted in the form of a photon.

When the electron falls back to its ground level the light is emitted.

Like any satellite, the slowing electrons would fall into the nucleus.

The excited electrons would fall back to their original levels and emit energy as light.

This causes the electrons to jump to a higher energy level and then fall back down and release light.

As a result, an electron could always radiate energy and fall into a negative energy state.

When the electrons fall back to lower energy states, a photon of light is emitted.

When the electron falls back to its original energy level, it releases a photon of light.

When the electron falls back to its normal level, it releases energy in the form of another photon.

When the electrons fall back to their original energy level, they emit light.