Make Gak: Experiment with Polymers

What You Do:

1. Help your child measure and mix 1/4 cup of water with 1/4 cup of white glue. Discuss how the two liquids change as the mixture is created.
2. Use caution during this step, as borax is harmful if swallowed. Help your child measure and mix 1/3 cup of warm water with 3 tablespoons of borax laundry booster. Stir until the borax dissolves. Discuss how the solid dissolved in the liquid, creating a new, second mixture.
3. Ask your child what he thinks will happen when the liquid glue mixture and the borax mixture are combined. Once he's had a chance to answer, gently and carefully poor the glue mixture into the borax mixture. Have your child turn the glue mixture over in the borax mixture several times, without stiring or mixing the two together, then fish out the glue mixture and knead it for several minutes.
4. Observe the resulting substance. Is it still a liquid? If your child holds it cupped in his hand, then opens his fingers, the mixture runs like a liquid. But if your child pinches the mixture, twisting sharply, he can tear off a piece, leaving a flat edge. Congratulations—you have created a polymer!

Your polymer will keep for several weeks in a sealed plastic bag or container.