1. Moving
Thermal
Energy

2. Differentiate between conduction, convection, and radiation.
GOALS
Explain common examples, such as ice in a soda, to show the direction of energy flow.
Explain molecular motion a s it relates to thermal energy changes in terms of conduction, convection, and radiation.
Intro Clip
Differentiate between conduction, convection, and radiation.
Determine the heat capacity of a substance using mass, specific heat, and temperature.
Use a calorimeter

3. Temperature conversions
Three formulas:
F=(9/5C) +32
C=5/9(F-32)
K=C + 273

4. What is energy? Energy is the ability to do work or in chemistry
the ability to move or change matter.
Properties of Energy
Energy is always conserved.
Energy can be transferred from one object to another or system by the interaction of forces
Example: digestion
Comes in multiple form. (KE or PE)
Potential energy = stored energy
Kinetic energy = energy of motion

5. Temperature and Heat
Temperature is the measurement of the avg. KE of the molecules in a material.
Heat is the transfer of KE from one material to another.
Film clip

6. Heat flows
from WARMER to
COLDER!

8. Conduction The transfer of thermal energy in solids.
Clip
The transfer of thermal energy in solids.
Materials must be in direct contact with each other!
Ex: Heating of the
bottom of a pot on stove.

10. Convection Transfer of thermal energy in liquids and gases.
clip
Transfer of thermal energy in liquids and gases.
The matter actually moves from one place to another.

12. Radiation
Clip
Transfer of thermal energy by electromagnetic waves (we’ll discuses these more later)
Transferring energy through space...NO MATTER IS REQUIRED!

14. REVIEW
Clip

15. Specific Heat Adding Energy to a material Causes the
Temperature to go up.
Taking energy away from a substance causes the temp. to
Go down!

16. Have you ever noticed that on a hot summer day the pool is cooler than the hot cement?
OR maybe that the ocean is cooler than the hot sand?
Why? The sun has been beating down on both of them for the same amount of time
It takes more thermal energy to raise the temperature of water that it does the cement!

17. Water absorbs a lot of heat energy before its temperature changes while sand needs little heat energy before its temperature increases.

20. Specific Heat
The amount of energy required to raise the temperature of a material (substance).
It takes different amts of energy to make the same temp change in different substances.
We call the amt required: Specific Heat!

21. Specific Heat of water
The Cp is high because H2O mols. form strong bonds w/each other.
It takes a lot of energy to break the bonds so that the the molecules can then start to move around faster (HEAT UP).

22. Example: Specific Heat of Water
Cp = 4,184 Joules of energy to raise the temperature of 1kg 1°C.
video clip
Why Cp?
Cp Stands for “Heat Capacity”

23. Calculating Specific Heat
The Greek letter Δ means “change in”

24. EXAMPLE : p162 Mass = 45kg Q = 203,000J Δt = 40°-28° Δt = 12° Cp = ?
Q =m x Cp x Δt
Q/(m x Δt) = Cp
Cp = 376 J/(kg °C)

25. Specific Heat Lab

26. Calorimeter

27. EOCT
QUESTION

28. A by traveling through space as waves
B by the movement of fluids
C by the expansion of gases
D by contact between particles

29. A copper ornament has a mass of 0
A copper ornament has a mass of kg and changes from a temperature of 20.0°C to 27.4ºC. How much heat energy did it gain?
A 200 J
C 540 J
B 460 J
D 740 J

30. Energy The capacity to do work or produce heat Kinetic Energy (KE)
Energy of motion
Anything in motion has KE
Potential Energy (PE)
Stored energy due to position or chemical nature

31. Measuring Energy Joule (J) is the metric unit for energy
calorie (cal) is the energy required to raise 1g H2O 1°C.
Calorie (Cal) is associated with food. 1Cal = 1000 cal.
1 cal = J

32. Measuring Energy Joule (J) is the metric unit for energy
calorie (cal) is the energy required to raise 1g H2O 1°C.
Calorie (Cal) is associated with food. 1Cal = 1000 cal.
1 cal = J