lines in electromagnetic spectrum

[RenuChepuru1L]

I was a little confused about what prof. Lavelle was saying today about how an electron when it falls or jumps an energy level has its energy emitted as a photon

[Mika Sonnleitner 1A]

When a light source is shined on a hydrogen sample, it has the potential to excite the electron from its ground state to an excited state. Or, the incoming energy from the photon can bring an electron down from an excited state to a less excited state (ex. n=4 energy level to n=2 energy level). An electron will only move from a ground state to an excited state if the incoming energy from the photon exactly matches the energy difference between the specified energy levels. If an electron moves up energy levels (ex. n=1 energy level to n=3 energy level), then it will absorb energy. However, if the electron moves down energy levels (ex. n=4 energy level to n=2 energy level), then it will emit energy in the form of light (photons).

Basically, if an electron jumps up energy levels, it absorbs energy. If it jumps down energy levels, it emits energy. The difference in energy is given off as a photon.