Grades 6-12. A chemistry lesson that is competitive? Yes! Bring the excitement of a Carolina STEM Challenge® to your chemistry classroom and watch student engagement bounce off the walls. Introduce students to polymer chemistry as they make bouncy balls using white glue and sodium borate. After testing their cross-linked polymer's properties, student teams are challenged to design a polymer that maximizes bounce. Kit materials support 15 teams, and the challenge requires 1 to 2 class periods.