Hunkins Experiments
Hunkin's Experiments: See if a Ring Is Pure Gold
Hunkin's Experiments is a group of simple cartoon illustrations of scientific principles. Some would work well in the classroom, but others have little value beyond entertaining students. All of the projects are easy to do. This one...
Tech Target
Whatis.com: Specific Gravity
This article tells what specific gravity and how to compute the specific gravity for solids, liquids, and gases.