electron promotion

In physics, excitation is the process of adding energy to a system, such as an atom or molecule, causing it to move from its lowest energy state (ground state) to a higher energy state (excited state). This added energy is called excitation energy.1

For an electron in a hydrogen atom, a specific amount of energy is required to move it from its ground state to a higher energy level. For example, 10.2 electron volts are needed to promote an electron to the first excited state. When an atom returns to its ground state, it releases this stored energy, often as visible light.1

This process is fundamental to how matter absorbs energy, such as light, and can be heated or ionized. The arrangement of electrons in orbitals, known as the electronic configuration, determines an atom's chemical properties. In some cases, like with carbon, an electron may be promoted to a higher orbital to form more bonds, even though this initial promotion requires energy.1234