Cool Science Experiments: Growing Crystals
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This two-ingredient project has a big WOW factor, and it’s become a favorite in our house. I am always on the lookout for cool science experiments for kids that I can do right in my kitchen. This growing crystals experiment fits the bill!
How to Conduct the Crystal Growing Experiment
You could make any shape, really, but we decided on bunny rabbits for Easter. Borax and boiling water are all it takes to grow crystals! And they are so sparkly and awesome.
You will need:
- Pipe cleaners
- Borax (found in the laundry section of stores)
- Boiling water
- Wide mouthed jars or other glass containers
- Food coloring (optional)
- Bend the pipe cleaner into the shape you want and tie a string to it. Attach the other end of the string to a pencil.
- Combine 1 cup of boiling water per 3 tablespoons of Borax. Our jars held 3 cups of water and 9 tablespoons of Borax. Stir until dissolved completely. Add food coloring, if desired.
- Drop the pipe cleaner bunny into the Borax solution, making sure that it is not touching the sides or bottom of the jar. Lay the pencil across the top of the jar.
- Let the experiment sit for at least 6 hours, or overnight. You will have beautiful, sparkly crystals all over the pipe cleaner.
- Carefully remove the pipe cleaner from the Borax solution and place it on a paper towel to drain, then on wax paper to dry further.
Caution: This experiment should be done with adult supervision. Borax can cause irritation if it gets in the eyes and is harmful if ingested. Avoid breathing Borax dust.
The food coloring made the borax and water mixture look pretty while the crystals were growing but it didn’t actually color the crystals. The crystals are actually white. It’s the color of the pipe cleaner that comes through.
Clean up: Crystals will also likely grow on the bottom of the jars. To loosen them, fill the jar with hot water and use a fork or butter knife to free them. We loved examining the handful of crystals that came from the jar bottoms.
The Science Behind the Experiment
The Borax crystals experiment creates a chemical reaction between two ingredients: Borax and water.
Solubility is the degree to which one ingredient can dissolve into another. In this experiment, we are dissolving Borax into water. The solubility increases as the temperature increases, so the boiling water makes the Borax more soluble.
As the water cools, the Borax separates from the water and settles on the pipe cleaner and the bottom of the jar, forming crystals. More crystals form on top of crystals. Isn’t that cool?