Use chemistry to make a bouncing polymer ball, then alter the procedure to see the effect the changes have on the characteristics of the bouncing ball.: Make a Bouncing Polymer Ball - Introduction and Materials
(image) What a great idea for the kids / grandkids! Perfect DIY project & recycle those used / broken crayon pieces, too. Would make for a great party favor, gift for Valentine's Day (or other occasions) or gift from Teacher to Students! Love it!