Density is a value for mass, such as kg, divided by a value for volume, such as m3. Density is a physical property of a substance that represents the mass of that substance per unit volume. When mercury, water and cyclohexane are mixed, three layers would be formed since they are not miscible with each other. The position of the layers depend on the density of the liquid. The uppermost layer would be the lightest which is cyclohexane. The middle layer would be water since it has a density intermediate of cyclohexane and mercury. The lowest layer would be mercury since it has the heaviest density.