1Add a few drops of food coloring to each cup of water to make 4 different colors.
2Add different amounts of salt to each cup of water. No salt in the first cup. 1 tablespoon of salt in the second cup. 2 tablespoons of salt in the third cup. And 3 tablespoons of salt in the fourth cup. Then mix up all the contents in each cup.
3To make layers, use the pipette to carefully transfer each of the layers into the test tube, one at a time.
4The liquid with the most amount of salt goes on the bottom, followed by the liquid with the second most amount of salt, then the third, and finally, add the liquid with no salt.
5To help the layers stay separate, add the liquid slowly and tilt the test tube to transfer the liquid down the side.
How It Works
You’ll see that the 4 layers of water stacked in separate layers. This works because each band of saltwater has a different density. Water with more salt is denser and will be at the bottom. The water with the least amount of salt is less dense, so it stays at the top. In the real world, ocean water can also vary in how much salt is dissolved in it. Areas near the poles can be saltier than areas near the equator. Differences in the amount of salt in ocean water can create ocean currents, which moves thermal energy around our planet.
Check out the Full Lesson on Climate Zones & Ocean Currents!
In this lesson, we learn that:
Climates are the result of the unequal heating and cooling of the Earth.
Circulation of the atmosphere moves a lot of thermal energy around the globe.
Circulation of water in the ocean (ocean currents) can also influence regional climates.