Heat: Transfer of Thermal Energy

Accept a range of answers. This should give you an idea of where your students are in their understanding. (Heat is the transfer of thermal energy from one object to another.) Students often have misconceptions about cold and may say cold is transferred between objects. Cold is just where there is less thermal energy.

Conduction, convection, and radiation

No, the chemical composition of the material and the amount of material affects the amount of heat the material will hold. For example, it takes more heat to raise the temperature of water than it does to raise the temperature of a metal. It would take more heat to raise the temperature of water in a bathtub full of water compared to a cup of water.

We are measuring the average kinetic energy of the atoms/molecules in a substance

Heat is transferred from the sun to Earth by radiation, because there is no medium (solid, liquid, or gaseous material) in space. The Sun emits light, and light energy is a form of electromagnetic radiation. The light energy warms the molecules of the atmosphere, the heat is then transferred by conduction. (Note: the Sun emits all forms of electromagnetic radiation except gamma rays. Visible light is probably the most obvious form of electromagnetic radiation students will know.)

Both thermometers will have the same temperature. Because there is no additional heat source, there will be no change in temperature. The mitten is an insulator, but it does not produce heat.

Thermal energy is the energy contained within a system due to the motion of the particles. Heat is the transfer of thermal energy from a warmer system/object to a cooler system/object.

The particles (atoms/molecules) that make up that object are moving slower. Heat has been transferred from the object to its surroundings or to another object.

The amount of material (mass) and its composition (what it’s made of).

Whatever heating method is used (gas, electric, fire, etc.) heats the air, causing the air molecules to move faster closer to the heat source. As the molecules gain more energy, they vibrate more and spread out, which makes those particles less dense, so they rise. As they get further from the heat source, the particles move more slowly, are closer together, and become more dense, so they sink. This process continues over and over causing the air molecules to circulate.

Bismuth, because when three cubes of the same mass were heated and dropped into the same temperature water, the water the bismuth cube was dropped in heated up much less than the water with iron or tin. A substance with a high heat capacity heats up and cools down more slowly.

Examples from the video include puffy jackets, emergency blankets, solar cookers, clothing irons, hot air balloons, fans in computers, and freezing a tongue to a pole.