Density in Nature

We've been learning about Democritus (above).  He discovered the concept of the atom.

To help us understand the concept of density in nature we poured oil, then water, then maple syrup into a glass.  The density of each liquid can be seen in this picture:

Because the atoms in oil are packed loosely, the water and syrup could pass through and settle below it.  It was the same with the water.  Atoms in the maple syrup are the most tightly packed, making it the heaviest.

Next we dropped several solids into the layers of liquids.  We predicted what would happen with each solid.  We started with the cork.  It floated on the top because its atoms are loosely packed, making it the lightest.  Next we dropped in the grape.  It settled on the top of the maple syrup.  The rock sunk to the very bottom, showing that is it even heavier than the syrup.  The rock's atoms are VERY closely packed.  The ice went to the top of the layer of the water, showing that the atoms in ice are more loosely packed than the atoms in water.