• Ask  permission from an adult
  • Wear safety glasses
  • Do not taste any of the ingredients
  • Tidy up when you have finished and then wash your hands

Ingredients:

  • borax (found in the laundry section of the store)
  • cornflour
  • white PVA glue
  • warm water
  • food coloring (optional)

 

Also:

  • measuring spoons
  • spoon or craft stick to stir the mixture
  • 2 small plastic cups or other containers for mixing
  • marking pen
  • watch with a second hand
  • metric ruler

 

Procedure

  1. Label one cup ‘Borax Solution’ and the other cup ‘Ball Mixture’.
  2. Pour 2 tablespoons warm water and 1/2 teaspoon borax powder into the cup labeled ‘Borax Solution’. Stir the mixture to dissolve the borax. Add food coloring, if desired.
  3. Pour 1 tablespoon of glue into the cup labeled ‘Ball Mixture’.
    Add 1/2 teaspoon of the borax solution you just made and 1 tablespoon of cornstarch.  Do not stir.
    Allow the ingredients to interact on their own for 10-15 seconds and then stir them together to fully mix.
    Once the mixture becomes impossible to stir, take it out of the cup and start molding the ball with your hands.
  4. The ball will start out sticky and messy but will solidify as you knead it.
  5. Once the ball is less sticky, go ahead and bounce it!
  6. You can store your plastic ball in a sealed  bag when you are finished playing with it.
  7.  Tidy up.
  8. Wash your hands

 

How it works
The PVA glue  molecules get linked together by the borax.
This linking is called polymerization.
The long chains of polymers get tangled together and cause stiffness in the material.

Most plastics are polymers.


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