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).
Entries in density (9)
What happens to hot and cold water when placed in room temperature water? What if the water is colored? Watch the video for a simple demonstration of the properties of hot and cold water.
The densities of different liquids can be easily demonstrated by making a density column. Steve Spangler has a splendid density column demo that I decided to make on a much larger scale. Instead of using a graduated cylinder I decided to use a fluorescent light bulb tube guard. To seal one end of the tube I used duct tape and Goop so that no liquid would leak out. Once the tube is ready, it's just a a simple matter of pouring the liquids into the tube according to their densities. Check out the video for the results and for some additional tips.
I picked up this in a toy shop. Students are fascinated by it and always wonder how it works. Once they learn about density, they figure it out pretty easily.