How do the densities of vegetable oil, water, and corn syrup help them to form layers in a cup? Students will carefully pour vegetable oil, water, and corn syrup in any order into a cup and discover that regardless of the order they are poured, the liquids arrange themselves in layers the same way. Students will then weigh the liquids and use their results, along with what they understand about density, to explain why the liquids form layers as they do.