What happens to the energy of an electron as it moves to a higher shell?

When an electron transitions to a higher energy shell, it must absorb energy. This increase in energy occurs because electrons are found in quantized energy levels, or shells, around the nucleus of an atom. Each successive shell represents a higher potential energy state for the electron.

As the electron moves to a higher shell, it is moving further away from the nucleus and into a region where the potential energy is greater. The energy absorbed can come from various sources, such as electromagnetic radiation (light) when the electron absorbs a photon. This process is governed by the principles of quantum mechanics, which dictate that electrons can only exist at specific energy levels and must gain a specific amount of energy to overcome the attraction of the positively charged protons in the nucleus.

Therefore, as an electron moves to a higher shell, its energy increases, confirming the correctness of the selected answer.