Question

What light-producing process occurs when a substance absorbs shorter-wavelength ultraviolet light and then gives off the energy as visible light?

Answer 1

fluorescence

A fluorescent light bulb produces visible light by fluorescence. Fluorescence occurs when a substance absorbs shorter-wavelength ultraviolet light and then gives off the energy as visible light. The compact fluorescent light bulb  CFL  in the Figure below contains mercury gas that gives off ultraviolet light when electricity passes through it. The inside of the bulb is coated with a substance called phosphor. Phosphor absorbs the ultraviolet light and then gives off most of the energy as visible light.