A bacterium was stained with a fluorescent dye The bacterium

A bacterium was stained with a fluorescent dye. The bacterium was illuminated with a light beam of wavelength
450 nm. The light beam the dye will emit in return will have a wavelength ________.
A. exactly 450 nm
B. longer than 450 nm
C. shorter than 450 nm
D. that cannot be predicted

Solution

Answer. B. longer than 450 nm

Fluoresence is a form of luminescence. It deals with emission of light by any substance. The substance could have absorbed light or any other electromagnetic radiation. In fluorescence, the emitted light has a longer wavelength than the absorbed radiation.