1. Heat
A Form of Energy

2. Molecules and Motion
The motion of atoms or molecules is called thermal energy.
The more motion, the more energy.

3. Heat
The movement of thermal energy from a warmer object to a colder one.

4. Forms of heat transfer
Three forms of heat transfer:
Conduction
Convection
Radiation

5. Conduction
Conduction involves the transfer of heat through direct contact.
Conductors allow heat to transfer, insulators do not.

6. Convection
Takes place in liquids and gases as molecules move in currents
Warm fluids rise and cold ones sink.

7. Radiation Heat is transferred through empty space.
Energy from the sun being transferred to the Earth.

8. Questions
What are the three types of heat transfer?
How is conduction different from radiation?

9. What type of heat transfer is involved?
Heating a room with a fireplace
Egg cooking in a frying pan
Roof of a house becoming hot

10. What type of heat transfer?
Warm air mass bringing a change in the weather.
Wire getting hot from an electric appliance.

11. Temperature and Heat
Kinetic energy is the energy of motion
Temperature is the measure of the kinetic energy of particles in a substance.

12. Thermometer A instrument used to measure temperature
Thermometers commonly have alcohol (with dye) or mercury
Digital thermometers have replaced older ones

13. Celsius Scale
Celsius is the metric scale for measuring temperature
Water freezes at 0ºC and boils at 100ºC

14. Kelvin scale
The Kelvin scale is a metric temperature scale measured in Kelvins (K)
Formula (273+ºC)= Kelvin

15. Questions
What is the formula for converting a Celsius temperature to a Kelvin temperature?
What is the boiling point of water on the Kelvin scale?
What is the freezing point of water on the Kelvin scale?

16. Absolute zero
The temperature in which all molecular motion stops (0 K)

17. Questions
Describe absolute zero.
What is absolute zero on the Celsius scale?

18. Temperature Joule is the unit for measuring thermal energy.
Energy, mass, and type of substance determine the amount of temperature change

19. Specific Heat The ability of a substance to absorb thermal energy.
Different substances absorb heat at different rates.
The greater the mass of the object the more heat can be absorbed.

20. Calculating Heat Energy
EnergyHeat =
Mass x Temp Change x Specific Heat
Mass in Kg
Temp change in Kelvins (K)
Specific Heat in Joule/Kg - K

21. Questions
How can heat be measured?
What is the unit used to measure heat?
What is specific heat?

22. Heat expansion
As atoms move faster, they take up more space.
Most solids, liquids, and gases expand as they are heated

23. Unusual Expansion of Water
Between 4ºC and 0ºC, water EXPANDS as it cools and turns into a solid.