Have you made flubber yet?   Here is an easy recipe for flubber.

Mixture One:
3/4/ cup warm water
1 cup white glue
food coloring


Mixture Two:
2 Tsp. Borax
1/2 cup warm water

Directions:
Mix up Mixture One in one bowl and Mixture Two in another bowl. Mix each mixture well.  Add mixture one to mixture two. Work together with your hands.  What you pull out is flubber!

Questions for Students: 
Is it a chemical or physical reaction?   (Can it be reversed?  Does it make a new substance?)

What can you do with it?
Try stretching it.  Try rolling it in a ball and bouncing it.  What else can you do?

Science Background for Teacher:  Flubber is made by a chemical reaction.  A chemical reaction occurs when a chemical substance changes into another substance with a different chemical identity.  Flubber is a special type of material called a polymer.  Polymers consist of a large number of similar molecules bonded together.   Polymers can have a variety of properties.  Examples of common polymers you might see everyday are plastic bottles, nylon, polystyrene, PVC pipes and the most famous silicone based polymer is probably Silly Putty.  Glue is comprised of linear polymer chains. When the borax that has been dissolved in water is mixed in, it causes those linear polymer chains of the glue to bind with each other creating cross-linked polymer chains.  Thus, flubber is a polymer created by a chemical reaction.   This particular type of polymer has properties that make in bendable and flexible.  

FREE Chemical Reaction Resource