Final answer:
When an electron in an atom jumps from the highest energy level to the lowest energy level, it gives off electromagnetic radiation with the greatest energy.
Step-by-step explanation:
When an electron in an atom jumps from a higher energy level to a lower energy level, it gives off electromagnetic radiation, such as light. The energy of the emitted radiation is directly related to the energy difference between the two energy levels involved in the transition. The greatest energy of electromagnetic radiation will be given off when the electron jumps from the highest energy level to the lowest energy level in the atom.