gas excitation

In physics, excitation is the process of adding a discrete amount of 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, known as excitation energy, can only be absorbed in specific, discrete amounts corresponding to the allowed energy levels of the system.1

Gas excitation specifically refers to the emission of light by a chemical element in a gaseous state. When a gas is electrically excited, its atoms absorb energy and jump to higher energy states. As they return to their ground state, they release this energy as photons, resulting in the emission of light. This phenomenon is responsible for the colors seen in gas discharge lamps, like neon signs, and also occurs naturally in phenomena such as auroras.2