My friend, Kollen, teaches preschool and always has great ideas that I like to steal! She came over yesterday for a visit and inspired me to try a liquid density science experiment. Here is the experiment in detail with even more liquid density experiments to do (if you want to go in depth for older children) and fun facts, etc.
What we basically did was fill three clear glasses. One with water, one with cooking oil, and one with corn syrup. Next I had the kids drop in various objects (paper clip, cheerios, pennies, etc) having them first make predictions on whether it would sink or float. I had made a simple chart for Luke to keep a log. Next I put blue food coloring in the water and red in the corn syrup. We then poured all three liquids in an old jam jar to see what would happen. Afterward they had fun taking turns shaking it.