Use glue, water, and Borax to create a polymer.
What type of reaction is the Borax solution having with the glue?
Measure 1 cup of water into the small bowl or cup and add the Borax powder. Stir it well and set it aside. You just made a solution of Borax.
Rinse your stirring spoon to get all of the Borax solution off of it.
In the larger bowl, measure 1/2 a cup of water and 1/2 a cup of white glue. Stir it well until it is all mixed together.
If you want colored slime, add 2-3 drops of food coloring to the glue mixture now.
Pour the Borax solution that you made in step one into the glue mixture and start stirring. You should see a big clump form in the colored glue right away, just keep stirring though until the clump has picked up as much of the liquid around it as it can.
Now comes the fun part – set your spoon aside and pick up the slime with your hands. Keep it over the bowl and knead it like dough, working it between your fingers. As you play with it, the slime will dry off on your hands and will become less slimy and more like putty.
Keep your slime in a plastic zip-lock bag in the fridge when you are not playing with it.