Your Safer Source for Science

Since 1977

Address P.O. Box 219 Batavia, IL 60510
Phone 800-452-1261
Fax 866-452-1436

Happy and Sad balls appear the same, but do they have the same properties? Bounce the balls, put them in the freezer, heat them in boiling water, compare their densities—observe the very interesting results.


  • Polymers
  • Density
  • Mass
  • Volume
  • Temperature
  • Specific Gravity
  • Materials Science