Which term describes a material that glows under ultraviolet light?

Which term describes a material that glows under ultraviolet light?

• A. Metamerism
• B. Opalescence
• C. Gamma phase
• D. Fluorescence

Answer: (D)

Fluorescence occurs when a material absorbs ultraviolet light and immediately emits visible light, producing a glow. The electrons are excited to a higher energy level and rapidly return to the ground state, releasing photons in the visible range (a process that happens essentially instantly). This glow fades quickly once the UV source is removed. Metamerism is about how colors appear under different light sources and isn’t about emission; opalescence refers to a milky, scattering-based appearance; gamma phase isn’t a standard descriptor for light emission. So the term that best fits a material that glows under ultraviolet light is fluorescence.

Fluorescence occurs when a material absorbs ultraviolet light and immediately emits visible light, producing a glow. The electrons are excited to a higher energy level and rapidly return to the ground state, releasing photons in the visible range (a process that happens essentially instantly). This glow fades quickly once the UV source is removed. Metamerism is about how colors appear under different light sources and isn’t about emission; opalescence refers to a milky, scattering-based appearance; gamma phase isn’t a standard descriptor for light emission. So the term that best fits a material that glows under ultraviolet light is fluorescence.