Grace and Jack made bouncy balls and through this experiment they learned that the balls they made, although they looked and felt like a solid, were actually not! Instead, their bouncy balls were something between a solid and a liquid called viscoelastic! They discovered that their bouncy balls eventually started flattening out when they were not touched.
Here is how Grace and Jack make their bouncy balls:
1) Mix 1/4 cup of white glue with a few drops of food coloring.
2) In a separate glass, dissolve 1 tablespoon of borax in 1/2 cup of warm water. Add 2 tablespoons of this mixture to the glue mixture and mix together. Grace and Jack played with this mixture for awhile before moving on to the next step.
3) Add a few drops of the extra borax mixture to the dough mixture made above and begin rolling it between your hands to form a ball. Continue rolling the ball until it is hard and dry enough so that if dropped, it bounces.
Here are some pictures of Grace and Jack making their bouncy balls...