Observations and results
Did each bag have some solid product (a polymer material) take form inside of it after mixing? Did bag C contain the solidest polymeric material, and did bag A contain the most liquidlike one?
Elmer's Glue contains polyvinyl acetate molecules, which are long polymer molecules that are tangled with each other. This is what makes glue viscous, or thick and sticky. When borax (sodium tetraborate) is added to polyvinyl acetate and cross-links the latter's molecules to each other, the glue solution becomes more viscous.
As borax cross-links more and more of the glue molecules together and they become more viscous, an increasingly larger and solid polymeric material is made from the reaction. The bag with the least amount of glue, bag A, should have been the most liquidlike, whereas the bag with the largest amount of glue, bag C, should have been the solidest. Store-bought Silly Putty and Slime are not made using polyvinyl acetate, but rather from organosiloxane polymers or polyvinyl alcohol to increase their durability.
The 50 percent glue solution and the glue and borax mixtures should not be poured down drains as they can form clogs. Dispose of them in plastic bags that you can throw in the garbage.
More to explore
"The Page That Dripped Slime" from Bizarre Stuff You Can Make in Your Kitchen
"Silly Putty: Synthesizing a Polymer" (pdf) from Louisiana State University.
"Making Things out of Polymers" from Polymer Science Learning Center, University of Southern Mississippi.
"Bouncy Polymer Chemistry" from Science Buddies
This activity brought to you in partnership with Science Buddies