The classic science experiment is called Layered Liquids. The premise is simple, heavy liquids sink and lighter ones float, and you can magically “layer” them. This is all due to the different densities of the liquids.
Layered Liquids Experiment
Layered Liquids Materials:
- Cookie sheets
- Corn Syrup
- Food Coloring
- Funnel (optional)
- Kosher salt (optional)
Layered Liquids Instructions:
- Place the jar in the middle of a cookie sheet. Depending on the jar you are using, a funnel may help when adding the liquids.
- Pour 1/4 cup or so of corn syrup into the jar
- Add 1/2 cup of water into your jar along with add some drops of food coloring.
- Add about a 1/4-1/2 cup of oil to the jar.
Turn it into a Lava Lamp:
Leave a little room at the top of your bottle/jar. Add in a tab of Alka Seltzer. Watch it create bubbles and movement in your “lava lamp.”
Another option for creating a “lava lamp” is to simply add salt. Since salt adds a bubbly gooey element when mixed with oil I let the kids put spoonfuls of kosher salt into the jars. It briefly created some lava lamp like bubble magic then sank to the bottom to form a sticky syrup/salt concoction.
The Science Behind Layered Liquids
Layered liquids showcases the concept of density. In fact this project is also often described as a density tower.
Density is defined as the mass per unit of volume of a substance. Mass is the amount of matter in an object or liquid. Density describes how heavy and close together the particles in a substance are.
Let’s take the example of water and oil. Both are liquids but both have very different densities. Water molecules are very closely packed while oil has more loosely packed molecules. For this reason water is heavier than oil and sinks below oil. If you combine liquids of different densities in a jar and shake them they will temporarily mingle. Allow the liquids to settle and they will naturally separate according to their density with some liquids sinking and others floating.
We made a more elaborate version of the layered liquids experiment (and it glows) here: Glow in the Dark Density Tower