Glow stick

The plastic casing covers the inner fluid.
The glass capsule covers the solution.
Diphenyl oxalate and fluorescent dye solution
Hydrogen peroxide solution
After the glass capsule is broken and the solutions mix, the glowstick glows.

A glow stick, also known as a light stick, chem light, light wand, light rod, and rave light, is a self-contained, short-term light-source. It consists of a translucent plastic tube containing isolated substances that, when combined, make light through chemiluminescence. The light cannot be turned off and can be used only once. The used tube is then thrown away. Glow sticks are often used for recreation, such as for events, camping, outdoor exploration, and concerts. Glow sticks are also used for light in military and emergency services applications. Industrial uses include marine, transportation, and mining.