Bouncy Balls

What you need:

• Borax

• Cornstarch

• Warm water

• Washable paint

• White school glue

• 1 small bowl

• 1 large bowl

What you do:

1. In the small bowl, mix 1/2 teaspoon of borax, 1 tablespoon of cornstarch and 4 tablespoons of warm water together.

2. In the larger bowl, mix 1 tablespoon of white school glue and a few drops of washable paint together.

3. Take your borax, cornstarch and water mixture and pour it into the larger bowl with the white school glue and washable paint.

4. Stir the two mixtures together.

5. As you stir, you'll notice a clump starting to form. Take the clump out and roll it into the shape of a ball.

   Tip: You'll notice it will feel soft, wet and sticky at first, but as you keep rolling it, it will start to begin to dry.

6. Let the ball sit for a few minutes so it hardens, then try to see how high it bounces!

   Tip: You can store the bouncy ball in a rounded container while it is drying.

Questions to ask:

1. What did it feel like when you mixed the cornstarch into the water?

2. How did the mixture change when you added all the ingredients together?

What's the science:

Glue is made of long, stretchy molecules called polymers. A polymer is made of many tiny parts that are linked together like a chain. When you add borax, it acts like a connector, linking those polymer chains together into a stretchy net. This net is strong enough to hold its shape but its also flexible enough to squish and bounce. Did you know, if you change the recipe, you change the bounce. More borax makes a firmer, bouncier ball while less borax makes it softer and gooier.