Radiation, Conduction or Convection

Radiation The transfer of energy as electromagnetic waves.

Conduction The transfer of thermal energy from one material to another by direct contact.

Convection The transfer of thermal energy by the circulation or movement of a liquid or gas.

Sometimes more than one method of energy transfer is taking place

The young woman in the pink dress was using a straightened out coat hanger wire to cook her marshmallow.

Metal is a good conductor of heat. The heat from the fire travelled along the thick metal wire. The wire got so hot that the student had to let go of it. The young woman in the blue dress is using a wooden rod to hold her marshmallow. Wood does not conduct heat well. The wood in her hand is still cool and the marshmallows are almost done!

Convection causes currents of warm and cool air to move. Notice how convection is happening in this pan. The process is the same in water and in air. It even happens in the hot magma inside the earth.

REMEMBER: Heat goes higher Hot air, hot water, and hot rock all tend to rise. Cold creeps lower. Cold air, cold water, and cool rock all tend to sink

There is visible and invisible infrared heat