The United Nations declared 2011 the International Year of CHEMISTRY, and in honor of that, here is a cool chemistry experiment that will amaze your friends—cool crystals that grow overnight! This experiment involves boiling water, so you will need an adult assistant (adult assistants are great whenever there is dirty work to do).
Here’s what you’ll need:
- borax (available as a powder in the laundry aisle of most large grocery stores—borax is also used in things like detergents, cosmetics and “science slime.”)
- pipe cleaners
- glass jar
- adult assistant that can boil some water (and some boiling water)
- food coloring (optional)
First you’ll need to create a crystal-growing borax solution. This is your adult assistant’s job. A “solution” is made when you dissolve something into a liquid. For instance, if you stirred salt or lemonade powder into water, you would be making a salt solution or a lemonade solution. In this case, you’ll be making a solution out of borax, a powder used in detergents and cosmetics. Borax is like soap. It is good at cleaning things, but you should not eat it or get it in your eyes.
Tell your adult assistant to boil some water. Warn your assistant that it is important to be careful to avoid burns. Once the water is boiling, tell your adult assistant to remove it from the heat source and carefully start to stir in borax powder. You’ll want to start with about three Tablespoons of borax powder for every cup of water. You need to “supersaturate” the solution. That means that you want to keep adding borax and stirring until the water can’t dissolve any more. Hot water can dissolve more borax powder than cold water because the molecules in hot water are moving faster and are farther apart, so they can more easily surround individual borax molecules. When the water cools down, it can’t hold as many borax molecules, and they start to come out of solution–in other words, they will stick to your pipe-cleaner to form sparkly crystals!
Once your solution is “super saturated” (You can’t dissolve any more borax, and there is a little bit left in the bottom) let it cool down a little until it is safe to handle. If you want, you can add a few drops of food coloring. While it cools, bend your pipe-cleaner into the shape you want. The shape will need to fit easily into your glass jar with a little room to spare.
Tie a string to your pipe-cleaner, and tie the other end of the string to the pipe cleaner, like this:
When the solution is cool enough to be safe, have your assistant carefully pour it into a large glass jar. Lower your pipecleaner into the jar of liquid. The Pipe cleaner should be totally submerged in the liquid, but no closer than an inch from the bottom of the jar (otherwise, when crystals form, the pipe cleaner might get stuck to the bottom of the jar.) Put the jar someplace where it can sit, undisturbed for a day or two. You’ll be able to watch crystals form!
Here is a picture of the pipe cleaner hanging from a pencil in the crystal growing solution. We added yellow food coloring to this solution.
After about 24 hours, you can lift your crystal shape out of the growing solution. Let the crystal hang in an empty jar or place it on a paper towel for a little while to dry. Wow! Check out your amazing crystals! It is OK to touch your crystal shapes, but be sure to wash your hands afterward before touching your eyes, nose, mouth, pets, or babies. Hang your crystal shape in the window and watch it sparkle! Isn’t Chemistry amazing?!
You can make any crystal shape you can think of. Here are some ideas:
Crystals that spell I ♥ C (for I love chemistry, of course!)
Did you try this experiment? Send pictures of yourself and your cool crystals—we might even post them on the website! Mail pictures to firstname.lastname@example.org