Heat and temperature
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1. Heat

Click on the image to explore the Hot Oven simulation.
Watch out! If you try to take the food of a hot oven you maus use an oven mitt.

Touching the baking pan with bare hands could cause a painful burn.
However, the air inside the oven doesn’t hurt. How can this be? Explore the Hot Oven simulation on the right to find out.

What Is Heat?

Heat is the transfer of thermal energy between substances.

Thermal energy is the kinetic energy of moving particles of matter, measured by their temperature.

Thermal energy always moves from warmer to cooler substances. You can see this in the figure below.
(a) Substances H and L are initially at different temperatures, and their atoms have different average kinetic energies. (b) When they are put into contact with each other, collisions between the molecules result in the transfer of kinetic (thermal) energy from the hotter to the cooler matter. (c) The two objects reach “thermal equilibrium” when both substances are at the same temperature, and their molecules have the same average kinetic energy.

L

N

N

C