Conduction, Convection, Radiation Chapter 6, Lesson 2

3 Ways Heat Transfers

Radiation The transfer of thermal energy by electromagnetic waves All matter radiates infrared energy. thermal energy can travel through empty space (vacuum), solids, liquids and gases

Conduction The transfer of thermal energy by collision of particles Particles with higher KE transfer energy to particles with lower KE Continues until the energy of all particles in contact are equal Occurs in solids, liquids and gases

Convection The transfer of thermal energy by the bulk movement of particles Occurs in fluids only

Combustion Engine- Where does Thermal Expansion occur?

What happens to a material when it is Heated or Cooled? Thermal Expansion When matter is heated, the temperature increases. The particles’ average KE increases. The faster particles spread out. The volume increases. Thermal Contraction When matter cools, the temperature decreases. The particles’ average KE decreases. The slower particles move closer. The volume decreases.

More Heat Transfer

Can occur in a vacuum Can occur in solids Can occur in fluids Requires particles conduction convection radiation

MiniQuiz-Conduction, Convection or Radiation? 1.The transfer of thermal energy from one material to another by electromagnetic waves 2.The cycle causing cooler water to sink and forcing warmer water upward 3.This can occur in a vacuum (empty space). 4.The transfer of thermal energy between materials because of collisions between particles 5.This is how heat was transferred from the foil to the chocolate chips in the demonstration.

6.When particles that have different KE collide, particles with higher KE transfer energy to particles with lower KE 7.The transfer of thermal energy by the movement of particles from one part of a material to another 8.Because space is a vacuum, this is the only way thermal energy can travel from the Sun to Earth 9.Only occurs in fluids 10.This occurs when you grab the hot handle of a metal pot cooking on the stove.