1. Conduction Convection & Radiation

2. Conduction
Conduction is the transfer of thermal energy by collisions between the particles that make up the matter
Particles must be in contact for conduction to occur
The particles in contact MUST have different amounts of thermal energy

3. What is happening?
High Energy particles collide with the Low Energy particles and directly transfer thermal energy.
High Energy
Low Energy

4. Example:
Conduction transfers thermal energy to the end of the spoon as particles with more kinetic energy transfer energy to particles with less kinetic energy
High Energy
Low Energy
Low Energy
High Energy

5. Conduction The best conductors of thermal energy are metals
This is why cooking materials are made out of metal
Silver, copper and aluminum are among the best conductors

6. Convection
Convection is the transfer of energy in a fluid by the movements of warmer and cooler fluid
*Fluids must flow = liquids and gases

7. Convection

8. Convection on Earth Convection currents drive our weather
Warmer (moist) air from the equator rises
As this air rises, it cools in temperature and loses moisture
Cooler (drier) air sinks down toward the ground
Temperature of falling air increases as it sinks

9. Radiation
Radiation is the transfer of energy by electromagnetic waves such as light or microwaves
These waves travel through space even when matter is not present

10. Radiation Energy transferred by radiation is called radiant energy
When you stand near a fire, radiation transfers energy from the fire and increases the thermal energy of your body

11. Radiation
When radiation strikes a material it can absorb, reflect or transmit some energy
This depends on the type of matter
Thermal energy increases when a material absorbs radiant energy