Fluorescence Definition

Chemistry Glossary Definition of Fluorescence

Fluorescent light
Fluorescent lights are coated with phoshors that absorb energy and release it as visible light. Verena Andrea Philipp / EyeEm / Getty Images

Fluorescence is luminescence that occurs where the energy is supplied by electromagnetic radiation, usually ultraviolet light. The energy source kicks an electron of an atom from a lower energy state into an "excited" higher energy state; then the electron releases the energy in the form of light (luminescence) when it falls back to a lower energy state.

Fluorescence Examples:

fluorescent lights, the red glow of rubies in sunlight, phosphors in television screens