MAKE A BOUNCY BALL   make these in our slime time party!  
more experiments

½ c. water

½ t. borax (a laundry booster; can be found at Walmart and most grocery stores)

2 T. school glue

food coloring

cup

spoon

paper towels

Procedure: Stir the water and borax in a cup until the borax is dissolved.  Mix coloring into your glue.  (Tip:  Making two or more colors of glue will make a very colorful bouncy ball!)  Drop your glue by the tablespoon into the borax solution, stirring the glue as it is pouring in.  As the glue hits the solution, it will solidify into a slimy substance.  Now have fish out the glue with your hands. If the glue is still sticky, dip it into the borax solution over and over until it’s all solid. The more you handle the slime, the firmer it will become. Eventually, you will be able to form it into a ball that bounces!

Extension:  Make a bouncy eyeball!  Use regular white school glue to make the eye.  Make a smaller batch of blue or green bouncy glue, and an even smaller batch of dark blue or black.  Use the blue or green blob to make the iris of the eye, and the dark blue or black to make the pupil!  Smush this into your white blob and you have a bouncy eyeball.

Extension:  To make a firmer bouncy ball, mix approx. ½ c. water and approx. 1 t. borax in a cup. Now put 2 T. of glue into this solution. The slime will be much firmer this time. Stir it well with a spoon, then take it out and work it into a ball.

The Science: 

• Rubber is made up of long chains of things called "polymers." These chains are like tiny, twisted strands of cold spaghetti. When a rubber band is stretched, the chains uncoil and straighten. When the rubber band is released, the chains coil up again. This is what makes rubber things stretchy and bouncy. The chemical reaction in our experiment today caused the glue to form polymers. Though not technically rubber, your bouncy ball shares many of the same characteristics!

• When a ball bounces, it is essentially squishing (when it hits the ground), then un-squishing (as it pushes back up). Several variables may make a ball less or more bouncy. One variable is the composition of the ball itself. Some matter, like rubber for example, has more spring to it than other matter (like chewed up gum).

• Bounciness can also be impacted by how a ball is built. For example, a soft basketball doesn't bounce as well as one full of air – even though both are made of rubber and air. That’s because when a soft basketball hits the ground, the energy gets spread around more than when a hard, fully inflated basketball hits – so there’s less upward motion.

• Bounciness can also be impacted by the ground. Hard, heavy balls don’t bounce as well on soft ground because their energy gets absorbed. But a steel ball will bounce well on a steel floor!

• Temperature can impact bounciness by making the material in the ball softer (heat) or harder (cold), or increasing/decreasing the air pressure inside the ball (because hot air takes up more space than cold air).