Question

3. What are fluorescent substances?​

Answer 1

Answer:

Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation. It is a form of luminescence. ... Fluorescent materials cease to glow nearly immediately when the radiation source stops, unlike phosphorescent materials, which continue to emit light for some time after.

Answer 2

Fluorescence, emission of electromagnetic radiation, usually visible light, caused by excitation of atoms in a material, which then reemit almost immediately (within about 10−8 seconds). The initial excitation is usually caused by absorption of energy from incident radiation or particles, such as X-rays or electrons.