1. Heat and Temperature
Notes

2. What are the molecules of matter doing all the time?
All matter is composed of continually jiggling atoms or molecules
The jiggling is random motion.

3. If something is vibrating, what kind of energy does it have?
Kinetic Energy
the energy of motion

4. What is temperature?
Temperature is the quantity that tells you how warm or cold an object is with respect to some standard.

5. The Celsius (Centigrade) Scale
Temperature at which water freezes (at standard atmospheric pressure)
100 º C
Temperature at which water boils (at standard atm. Pressure)
100 equal parts called degrees
Centigrade (100 degrees)

6. The Fahrenheit Scale 32 º F 212 º F
Temperature at which water freezes (at standard atm. Pressure)
212 º F
Temperature at which water boils (at standard atm. pressure)
Greater precision when reporting temperature with whole numbers since the degrees are smaller

7. The Kelvin Scale (or the SI Scale)
Lord Kelvin
British Physicist
Absolute Zero
0 Kelvin (0 K)
No kinetic energy
No molecular motion
0 K = -273°C
Degrees are the same size as Celsius degrees

8. What does temperature really measure?
Random motion of molecules in a substance
Average kinetic energy per molecule

9. How does a thermometer work?
Measures temperature by means of expansion and contraction of a liquid.
Energy flows until thermal equilibrium (same temperature) is reached
Small thermometer relative to object so its temperature doesn't drastically change the temperature of the object.
Registers its own temperature

10. Matter contains…
Matter contains thermal energy (or internal energy

11. What is heat?
Heat is the transfer of thermal energy of one thing to another because of a temperature difference.

12. How do you know the direction of energy transfer between two objects in thermal contact?
Direction of energy transfer is based on temperature
Direction of energy transfer is always from a warmer thing to a neighboring cooler thing

13. What happens when a substance absorbs or releases thermal energy?
Different things may happen
Increase or decrease in kinetic molecular energy (temperature change)
Phase change (change in the structure of the molecules)

14. What is thermal equilibrium?
After objects in thermal contact with each other reach the same temperature, heat no longer flows between them and we say that the objects are in thermal equilibrium.

15. The End