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Science_Lab_Yellow / Lesson 7: Materials that Conduct Heat

Materials that Conduct Heat
What will we be learning today?

  • In this lesson, we are going to learn all about what materials conduct heat well.

What Materials Conduct Heat Well?

  • The photograph shows very hot tea in a foam cup. A metal spoon has been sitting in the tea for some time. The outside of the cup is slightly warm. However, the spoon's handle is almost too hot to hold. Why has more heat flowed into the handle of the spoon than into the walls of the cup?

  • As you learned, some materials are better at conducting heat than others. The metal spoon is a good conductor of heat. However, the foam cup is a poor conductor of heat. As a result, heat flows quickly from the hot bowl of the spoon to its handle. However, heat flows very slowly from the tea into the foam.

    • Metals are the best conductors of heat. Why do metals conduct heat so well?

    • Heat is carried through a material by the motion of molecules. When a metal is heated at one end, the molecules move about rapidly. They collide with their neighbors, spreading the motion through the material. The spreading of the motion warms up other parts of the material.

    • The molecules in solids are packed very closely together. This makes transferring energy easier.

    • You have learned that the molecules in gases are spread apart. They cannot transfer heat between one another as easily as in liquids and solids. This explains why air is such a poor conductor of heat. Gases are the poorest thermal conductors of all.

    • Look at the table to see how well common materials conduct heat.

    Let's Review What We Learned Today!

    • Now complete your worksheet!