Today students completed our Convection Lab. They filled a tub with tap water; underneath was a sequence of Styrofoam cups filled with hot or cold water. Then they added a small scoop of potassium permanganate (food coloring works too!) above each of the cups. Before long, the water began to move. The difference in temperature caused the formation of convection currents. As the water molecules gained energy, they spread out, becoming less dense and rising to the surface. Then the water cooled off, becoming more dense and sinking back to the bottom of the tub. Convection will be an essential part of Unit 6. It happens in the ocean, in the air, and even underground. Hopefully this lab gives students a solid foundation for understanding all of Earth’s convection systems.
March 21 – Convection Lab (pg604).docx