Poly Density Bottle

 I bought a Poly Density Bottle kit I use as a demo to explain density or as a discrepant event.  But the kit is pricey.  Only recently did I learn about using UV beads with plastic, pony beads (8 mm).  Flinn has instructions here.  The UV beads have a different plastic composition, giving them a different densities.  Isopropyl alcohol is rubbing alcohol.  50 grams of pony beads are roughly 180 beads.  Below is a screenshot of a Chem teacher who has her students use test tubes, with instructions.  So much fun!