Students use the physical property of density to explain how the Earth's layers stack according to their varying densities. Six liquids are used to represent the mechanical layers of the Earth - Lithosphere, Asthenosphere, Mesosphere (upper and lower mantle), Outer Core and Inner Core. Students collect mass and volume of each liquid, calculate density, and "stack" the layers accordingly. They relate the density, and "stacking", of the liquids to the layers of the Earth. Teacher notes and measurements provided to build a model of the layers within a one liter bottle.