You see glow-in-the-dark things in all kinds of places, but it is most prevalent in toys. In the dark they will glow for 10 minutes. Usually it is a soft green light, and it is not really that bright. You need to be in almost complete darkness to notice it.
All glow-in-the-dark products have phosphors. A phosphor is a substance, which radiates visible light after being energized. The two places where we most typically see phosphors are in a television screen or computer monitor and in fluorescent lights.
Chemists have created chemical substances that behave like a phosphor.