posted by Leigh .
When a certain material is illuminated with visible light, electrons jump from lower to higher energy states in atoms of the material. When illuminated by ultraviolet light, atoms are ionized as some of them eject electrons. Why do the two kinds of illumination produce such different results?
UV light has more energy than visible light; therefore, the UV light has the potential to move the electrons far enough so that the electrons are in an ionized state.