1. Heat & Heat Technology Chapter 13

2. Temperature  Measure of the average kinetic energy of the particles in an object  Same average kinetic energy = equal temperature

3. Thermal expansion  Increase in volume of a substance because of an increase in temperature

4. Absolute zero  The lowest temperature on the Kelvin scale  0 K (about -273.16°C )  Temperature where all molecular motion stops  Not possible to reach it

5. Converting temperatures Celsius to Fahrenheit °F = (9/5 x °C) + 32 Fahrenheit to Celsius °C = 5/9 x (°F – 32) Celsius to Kelvin K = °C + 273 Kelvin to Celsius °C = K – 273 Freezing point of water 32° F 0° C 273 K

6. Heat  The energy transferred between objects that are at different temperatures

7. Thermal energy  The total kinetic energy of the particles that make up a substance  Measured in joules (J)

8. Thermal conduction  The transfer of thermal energy from one substance to another through a material or direct contact

9. Thermal conductors  A material through which energy can be transferred as heat  Example: metals  Curling iron  Cookie sheet  Iron skillet  Copper pipe  Stove coil

10. Thermal insulators  A material that reduces or prevents the transfer of heat  Examples  Flannel shirt  Oven mitt  Plastic spatula  Fiberglass insulation  Ceramic bowl

11. Convection  Transfer of thermal energy by the circulation or movement of a liquid or a gas  Convection causes the repeated rising and sinking of water during boiling  Wind is a result of earth heating by sun

12. Radiation  Transfer of energy by electromagnetic waves like in visible light or infrared waves

13. Specific heat  Amount of energy needed to change the temperature of 1 kg of a substance by 1°C

14. States of matter  The physical forms in which a substance can exist  Particles move at different speeds  The “state” of a substance depends on  Particle speed (kinetic energy)  Attraction between particles (potential energy)  Pressure around particles

15. 3 familiar states of matter  Solid  Liquid  Gas

16. Change of state  A change of a substance from one state of matter to another  Physical change only  Just affects physical properties but NOT the identity of the substance (i.e. water is still water whether it is a solid, liquid, or a gas)

17. Changes of state Freezing: liquid to solid Melting: solid to liquid Boiling: liquid to gas Condensing: gas to liquid

18. Insulation  Material that reduces the transfer of thermal energy (i.e. less heat passes into or out of)  Used in walls, ceilings, and floors  Helps houses stay warm in the winter  Helps houses stay cool in the summer

19. Heat engine  Machine that uses heat to do work  Fuel combines with oxygen (O 2 ) in a chemical change that releases thermal energy

20. Thermal pollution  Excessive heating of a body of water caused by human activity  Happens with large power plants that are near bodies of water  Harms animals living in water