Final answer:
An electron jumps from a lower energy level to a higher energy level when a photon is absorbed by an atom. This is known as excitation. The electron can later transition back to a lower energy level, emitting a photon with the corresponding energy difference.
Step-by-step explanation:
When an electron jumps from a lower energy level to a higher energy level, a photon is absorbed by an atom. This process is known as excitation and occurs when the atom receives energy from an external source. The absorbed photon raises the electron to a higher energy orbit, putting the atom in an excited state. The electron can later transition back to a lower energy level, emitting a photon with the corresponding energy difference. This process is referred to as de-excitation or emission.