This is a great activity to use density as a characteristic property to identify pennies that are mostly copper (pre-1982) and mostly zinc (post-1982).
Main topics include: mass, volume, density, characteristic property.
Students will measure mass and volume of different groups of pennies to calculate density, and using a chart of known metals determine which pennies are "real" and which are "fake." They enjoy the detective work!
If you like this activity, you can follow these links to other lessons and activities in my density unit.
Density Notes PowerPoint Presentation
Buoyancy Notes PowerPoint Presentation
Aluminum Boat Challenge
Density Lab I
Density Lab II