Some of our favorite science experiments have to do with the exploration of density. Density is a measurement of how many molecules are in a substance and how closely they are packed together. Substances built with tightly packed molecules are more dense than things built with molecules that are spread farther apart.
A fun way of thinking about this is by looking at the planet Saturn. Even though Saturn is WAY bigger than Earth, the molecules that make up its gaseous nature are less dense than the molecules that have built Earth. If our oceans were large enough to hold the planet Saturn, it would float on the water’s surface!
Exploring density is a really fun way to experiment, and with the colors of the rainbow, you can bring the magic of the holidays into your science project! For this rainbow column of Christmas Science, you’ll need the following items:
Tall glass or vase (we used a cylindrical vase)
Objects of various weights to be added to your column! We used glittery Christmas decorations, a bottle cap, a birthday candle, a lump of clay, a bead, and a popcorn kernel.
Liquids of various densities!
Add these liquids in order of appearance:
Light corn syrup (or honey)
Liquid dish soap
1. Pour the liquids very slowly into the container, in the order listed above. After the first liquid, you will want to tilt the container slightly to its side. This allows the subsequent liquids to slowly fall to the lower layers, without mixing.
2. Before you add the water and rubbing alcohol, add your food coloring to it! Because of the different densities of the liquids, you will notice a difference with how the food coloring disperses into it!
3. Once you have your rainbow column of Christmas density, start adding things into it! Carefully drop your items, one by one, into your column. See where they stop in the column!
As we learned before, density is a measurement of mass, or the relative heaviness of an object with a constant volume. Simply put, density is a measure of how much “stuff” is in something. That “stuff” pertains to atoms and molecules, which make up the mass of an object!
In each of the liquids, the atoms are aligned together in different distances. In the densest liquids (the bottom layers), the atoms that make them up are packed much closer together than the liquids in the upper layers. The upper layers then “float” on the lower layers, because the atoms that make them are farther apart!
The items that you add to your column also have different densities! That’s why some of them will stop at various layers. They’ve reached a point where the liquid below them is denser than they are.
If you’d like to learn more, check this out! We’ve done some really cool experiments to explore density and properties of matter. All it takes is a few standard kitchen ingredients, and a lot of scientific exploration!