Learners experiment with a piece of Silly Putty® by stretching, bouncing, and snapping it. They then create flubber, a similar substance, by mixing diluted glue and a solution of sodium borate. Learners investigate the similarities and differences between the two polymers, including that Silly Putty is a silicon (Si) polymer and flubber is a carbon (C) polymer. Both have the properties of both a liquid and a solid, where they flow like a liquid or can be stretched slowly. This is because the molecular chains are loosely arranged and can slide past each other. If pulled quickly, the molecular chains break away from each other instead of sliding.