2 types of Heat Energy2 types of Heat Energy

Kinetic Energy – is energy in motion. Kinetic Energy – is energy in motion. Temperature is the average KE of Temperature is the average KE of moleculesmolecules

Potential Energy – is energy in storage Potential Energy – is energy in storage aka latent heat or hidden energy. Cannot aka latent heat or hidden energy. Cannot be measured with a thermometerbe measured with a thermometer

Change in State (Phase Change)Change in State (Phase Change)

Change in state is a change in potential Change in state is a change in potential energyenergy

Known as latent heat because it does not Known as latent heat because it does not cause a temperature changecause a temperature change

During the phase change energy can be During the phase change energy can be absorbed or released but the energy is absorbed or released but the energy is hidden because it hidden because it DOES NOT SHOW A DOES NOT SHOW A CHANGE IN TEMPERATURECHANGE IN TEMPERATURE

DURING CHANGE OF STATE, ENERGY IS CONVERTED TO POTENTIAL ENERGY OR STORED HEAT – DOES NOT SHOW A CHANGE IN TEMPERATURE

Condensation and freezing – release energy Evaporation and melting – require energy

¾ OF THE ENERGY ABSORBED BY ¾ OF THE ENERGY ABSORBED BY EARTH EVAPORATES WATER FROM EARTH EVAPORATES WATER FROM

THE OCEANSTHE OCEANSEVAPORATION EVAPORATION 540 CALORIES/GRAM GAINED540 CALORIES/GRAM GAINEDThe gram of water absorbed 540 calories of latent The gram of water absorbed 540 calories of latent heat as it changed to vapor (heat as it changed to vapor (require addition of energyrequire addition of energy)) COOLING EFFECTCOOLING EFFECT

CONDENSATIONCONDENSATION 540 CALORIES/GRAM RELEASED540 CALORIES/GRAM RELEASEDThe gram of water released 540 calories of latent The gram of water released 540 calories of latent heat as it changed to liquid (heat as it changed to liquid (give off energygive off energy)) WARMING EFFECTWARMING EFFECT