If you don't have any baby food jars and you don't have a baby who will empty some jars for you, we suggest that you buy a jar of strained peaches or applesauce baby food. You can empty the jars over vanilla ice cream for a tasty dessert or mix them in a blender with milk and ice to make a smoothie. If you don't want to buy baby food, we have also done this experiment using two identical small, clear, drinking glasses. You just have to make sure that the mouths of the glasses match up perfectly, without a leak. If you've already made a Salt Volcano or a Glitter Globe , you probably know that some liquids float on top of other liquids.
Oil floats on water.
Alcohol floats on oil. That's because these liquids have different densities. Whenever you put together two liquids that don't mix, the liquid that is less dense will float on top of the denser liquid. A drop of oil weighs less than a drop of water the same size. The oil is less dense than the water, so it rises to the top.