Chemical Changes with Glo Sticks

This is one of the easiest, yet best, wow-moments for my class. When we're studying chemical changes, we talk about how to identify whether a chemical change has taken place. And, while I love using the Pancakes lab from Picture-Perfect Science, this little demonstration is great for introducing the topic (especially after they've read the text in this book that discuss light emission as being one way to identify a chemical change).


Grab yourself a package of glo-sticks from Dollar Tree (I tossed a couple of packages in there to last a few years) and pick your favorite color. The science behind the glo-sticks is very simple: you have a glass tube inside of a plastic tube. The glass tube holds a colored chemical and the plastic tube holds another chemical. When you bend the glo-stick, the snap you hear is the glass breaking. The two chemicals mix and - viola! - light is produced.

So, get your materials ready: your glo-stick, foil (it enhances the light!); scissors; and a paper towel.

Safety Note: I don't recommend getting the chemicals on your hands. But, honestly, I have. Nothing happened. I was, however, quick to make sure I washed my hands. I do this lab as a demonstration in my class just in case a student were to have a reaction to the chemicals. Read up on Steve Spangler's discussion on glow-sticks. He also includes the exact chemicals that are contained in most glow-sticks. He cautions against opening them up to get at the chemicals...hence why I do this as a demonstration in my class. That, and you're breaking glass... having students do that would just be plain irresponsible.

Make sure you zoom your document camera in so the kids can see the small, transparent/translucent puddles clearly.

Being careful to not cut the glass tube, snip the ends off the plastic tube and let the clear liquid drain onto the foil into a puddle.

Let the glass tube slide out and dry it on the paper towel. Then, break it in half. The liquid tends to remain in the tube until you break the ends off. Let the colored liquid in both of those drain out into one puddle. (Blue is usually clear instead of colored.)

Turn off the lights.

Using the left over tubes or a clean toothpick, start pushing the liquids towards each other. Just when they meet, they'll glow. You can then push the puddles together and play with it.

Okay, I enjoy this part more than the kids. After all, they're not getting to touch this lab!! Have fun!!!