Chapter 16 Thermal Energy and Heat

1. Chapter 16 � Thermal Energy and Heat

2. 16.1 Thermal Energy and Matter Heat � transfer of thermal energy from one object to another because of temp. difference Heat flows spontaneously from hot objects to cold objects

3. Temperature � measure of how hot or cold an object is compared to a ref. pt. Related to avg. KE of the particles in an object due to their random motion through space Thermal energy � total PE and KE of all the particles in an object

4. Thermal contraction � when the volume of a material decreases due to a decrease in temperature Thermal Expansion � increase in the volume of a material due to increase in temp.

5. Specific heat � amt. of heat needed to raise the temp. of 1g of a material by 1 degree celsius

6. Heat (Q) = m x c x ?T mass x spec. heat x change in temp Math Practice � p.477

7. 16.2 Heat and Thermodynamics Conduction � transfer of thermal energy with no overall transfer of matter Occurs within a material or between materials that are touching Occurs slower in gases than in liquids or solids Thermal Conductor � material that conducts thermal energy well Thermal insulators � poor conductor of thermal energy

9. Convection Convection � transfer of thermal energy when particles of a fluid move from one place to another

10. Convection currents � occur when a fluid circulates in a loop as it alternately heats up and cools down Important in many natural cycles such as ocean currents, weather systems, and movements of hot rock in Earth�s interior

12. Radiation � transfer of energy by waves moving through space All objects radiate energy Rate at which energy radiates increases with temp.