Glow sticks generate light with very little heat, just like the glow you see from fireflies, jellyfish, and a few species of fungi. Chemiluminescence means light that comes from a chemical reaction. When this happens in animals and plants, it’s called bioluminescence.
In a glow stick, when you bend it to activate it, you’re breaking a little glass tube inside which contains hydrogen peroxide (H2O2). The tube itself is filled with another chemical (phenyl oxalate ester and a fluorescent dye) that is kept separate from the H2O2, because as soon as they touch, they begin to react. The dye in the light stick is what gives the light its color.
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Materials:
- Cool Blue Light Kit
- Corroded Penny
- Paper towels
- Water
You’ll need a really dark room to see this reaction take place, as the amount of light it gives off is low, but it’s still there! Allow your eyes to adjust to the darkness for about 10 minutes, and you’ll definitely see a blue glow in the liquid.
The light comes from the copper sulfate reacting with the luminol, and will continue until one of the reactants is used up.
For advanced students, you can do this experiment with Cold Light.
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