The document discusses kinetic molecular theory and heat transfer. It explains that all matter is made of molecules that are always in motion, and their motion increases with temperature. Heat is a form of energy caused by molecular motion, and it transfers from hot to cold through conduction, convection, or radiation. Temperature is a measure of average molecular motion or energy, while heat is the total energy of that motion.

1. Kinetic Molecular Theory
•All matter is made of molecules
•These are always in motion
•Their motion is directly related
to temperature.
•Demo

2. Heat Defined
•Heat is a form of energy
•It is caused by the motion of
molecules
•Give credit to: Count Rumford
(aka: Benjamin Thompson)
•Heat is a kinetic energy

4. Heat Transfer
• Heat moves from hot to cold.
• It can do this through:
– Conduction
– Convection
– Radiation

5. Conduction
When there is
direct contact
between objects
and heat is
transferred.

6. Convection
When there is
transfer of heat in
fluids
The hot fluid rises,
due to its lower
density

7. Convection Cells

8. Radiation
When heat moves
as an
electromagnetic
wave

9. Temperature Versus Heat
•Temp. is a measure of the
average velocity of the
molecules
•Heat is a form of energy
caused by this motion

10. ..the
higher the temperature, the
more energy something has
But…
… temperature is NOT a direct
measure of the amount of heat

11. Measuring heat
• Heat is measured in calories
• A calorie is 4.19 joules
• A calorie is how much heat is
needed to get one gram of
water to go up one degree
Celsius.

12. Think about this…
• You have a swimming pool
that is 10º C
• You have a cup of hot cocoa
• Which has a higher
temperature?
• Which has more heat?

13. Temperature Versus Heat
• Heat= total energy
• Temperature= average energy

14. Temperature Scales
• Fahrenheit
• Celsius
• Kelvin
• link
Ab zero
Bases

15. Specific heat
• An indicator of how
hard/easy it is to get a
substance to go up or
down in temperature

16. Specific Heat
• The amount of heat needed to
raise 1 gram of a substance by
1° C
• Unit= cal / g° C
• Water is easy, it is:1 cal / g° C

17. Calorimeter
• A device to measure heat
• All you do is measure water
and see how much it goes up
in temperature

18. Calorimeter
•The heat lost by an object is
gained by the water in the
calorimeter
• Equation for Heat lost or gained:
=Mass x ΔT x specific heat