This is a great experiment to show different densities of liquids. Have students record their predictions then watch as students create a rainbow in a glass. Liquids with higher densities will sink to the bottom while lighter liquids will go to the top.
Neat experiment to teach children about how to maintain healthy teeth. Use Coffee and Soda (with a boiled egg) and vinegar (raw egg) and leave overnight. Try brushing off stains on the boiled eggs, the raw egg explains decay!