Editing Density Rainbow (section)

== Why This Works ==

''Density'' is equal to the mass of a substance divided by the volume it takes up. Water has a density of 1kg/L, and can be used as a base for finding how dense other liquids are. Liquid soap and corn syrup are both more dense than water, so you will see them fall underneath it, while oils are less dense than water, so the lamp oil and vegetable oil would float on top. solid objects have differing densities as well. When the paper clips or other small objects are dropped in, they will sink below some layers and float on top of others! How well an object floats is what we call ''buoyancy''. If we know the buoyancy of an object, then we can calculate the mass of the object.

The sugar water variation of this demo is a great way to show that liquids that look the same can have different densities. The sugar water does not take up much more volume, or space, than the regular water. However, the sugar water has more mass per volume than the regular water, which means that it has a higher density. The more sugar there is dissolved in solution, the more mass there is per volume, and therefore the density will get higher.

The temperature version of this demo shows the students how a substance can change in density if the temperature changes. If something is hot, then the atoms and molecules have more energy, and can take up ''more'' space, or volume, while having the same amount of mass, and there be less dense. Likewise, if a substance is cooled down, then it will take up ''less'' space, or volume, with the same amount of mass, and be more dense! By simply heating up or cooling down a solution, we can affect the density of it!