Question

When an electron in a quantum system drops from a higher energy level to a lower one, the system ____.

emits an electron
emits a plasmon
emits a photon
emits a neutron

Answer 1

emits a photon

Step-by-step explanation:

When an electron in a quantum system drops from a higher energy level to a lower one, the system emits a photon. According to the law of conservation of energy, the energy of the emitted photon is equal to the difference in energy between the two energy levels:

`\Delta E= E_1 -E_2`

The opposite transition can also occur: the system can absorb a photon such that the electron jumps from the lower energy level to the higher level. As before, the energy of the emitted photon is equal to the difference in energy between the two energy levels:

`\Delta E= E_2 -E_1`