Fill the jar about halfway up with water and add a few drops of food coloring for contrast. Add about half as much vegetable oil to the jar and watch it float to the top. Now, a spoonful at a time, add salt to the jar. The salt will pull some of the oil down with it, but will release the oil as it dissolves and the oil will float back to the top. This will make your science experiment look like a real lava lamp. Keep adding salt to make it keep working. Now, try adding sugar or even sand. Kosher salt worked really well!
What worked the best for you? Do you know why oil floats to the top of the water? Email me your answers in the comments section of this post for a chance to win a KITCHENPANTRYSCIENTIST.COM tee shirt (size M.) I’ll do a drawing for a winner in two weeks! Thanks to PBSkids/DragonflyTV’s website for this fun idea. Check out their website for more great kids’ science!