Soda Can Density Discrepancy

Demonstrating the density of diet sodas versus regular sodas is a classic, but something unexpected happened when I placed a can of Dr. Pepper and A & W root beer in a tank of water. They didn't follow the usual pattern of results. Watch the video and please respond if you can provide an explanation for the results.

Stacking Liquids

Can saltwater, water, alcohol, and shampoo be stacked? This is a very simple student inquiry activty (and one of my students' favorites) that can be done in class (download handout).