Download Chapter 9 and 10

Chapter 9 and 10- Heat! Study Guide
PART I Directions: Pick the definition in column B that best matches the word in column A. Write the
letter of the definition on the blank line.
A
1. convection
F
2. radiation
E
3. conduction
B
4. heat
I
5. temperature
G
6. Celsius
C
7. Kelvin
A
8. Fahrenheit
9. calorie
J
H
10. calorimeter
D
B
a. A temperature scale based on absolute zero.
b. The transfer of heat energy through direct
contact.
c. A temperature scale based on the freezing
and boiling point of water.
d. A device used to calculate the amount of
heat energy stored in food.
e. The transfer of heat energy through the
emptiness of space.
f. The transfer of heat energy through a liquid
or gas.
g. The measure of how hot or cold something
is.
h. The amount of energy needed to change the
temperature of one gram of water one degree
elsius.
i. Energy that is based on the temperature and
mass of an object.
j. A temperature scale based on the freezing
point of water at 32 degree
PART II: Identify if the following situations are examples of heat transfer by conduction, convection, or
radiation. Circle your answer.
1. The spoon is too hot to touch after sitting in the hot soup. (conduction, convection, or radiation)
2. The moon’s surface becomes hot. (conduction, convection, or radiation)
3. Your feet hurt after walking barefoot across the beach. (conduction, convection, or radiation)
4. Bacon cooks in the frying pan. (conduction or convection, or radiation) (there is some convection
happening in the fat as it coats the pan)
5. The room becomes warm when the furnace is turned on. (conduction, convection, or radiation)
PART III Directions: Answer the following questions with a short answer.
1. Sidewalks are built with spaces between each section. Why?
As the concrete heats up, it will expand (thermal expansion) and as it cools down it will
contract. Space is needed for this to happen
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2. The cap on the jar is stuck, but if we run it under hot water we can unscrew the metal cap.
Why?
By heating it up, the molecules begin to move faster, spreading out more. This causes thermal
expansion, making the jar easier to open.
3. Which contains the greatest amount of thermal energy, a cup of water at 90 degrees C or a
huge lake at 40 degress celcius? Why?
The mass of the lake is much greater, meaning total energy is much greater.
4. Describe each of the three temperature scales: Fahrenheit, Celsius, and Kelvin.
F: used in US, not used in science
C: Based on boiling and melting points of water
K: Same as celcius, but adjusted so there are no negative values. Absolute zero = 0K
5. Heat and temperature are not the same thing. How are they different?
Heat is the transfer of thermal energy from one object to another and temperature is the
average kinetic energy (how hot or cold) of the molecules of a substance.
6. State the three laws of thermodynamics below:
1st Law: Whenever heat flows into or out of a system, the gain or loss of thermal energy equals
the amount of heat transferred
2nd Law: Heat never spontaneously flows from a cold substance to a hot substance
3rd Law: No system can reach absolute zero
7. What is a change of phase, or state? Is this a chemical or physical change?
When an object goes from one state of matter (solid, liquid or gas) to another. Physical.
8. Explain the difference between a conductor and an insulator. Include how the electrons are
positioned in each.
Conductors allow heat/electricity to easily flow through them because they have loosely held
electrons. Insulators do not allow heat or electricity to easily flow through them because their
electrons are tightly held to the molecule.
9. Explain why the water at the beach is cooler than the sand on the beach. Make sure you use
specific heat in your answer.
Water has a much higher specific heat capacity than sand, so it takes a lot longer for the water
to heat up than it takes the sand.
10. Describe the three forms of heat transfer: conduction, convection, and radiation.
Conduction: Heat transfer from direct contact between object and heat source
Conduction: Heat transfer in fluids through currents
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Radiation: Heat transfer by electromagnetic waves
11. An ice cube is in the Solid phase.
12. Solids have a Definite shape and Definite volume.
13. Describe how the molecules are arranged and moving in the solid phase. Include a picture with
your description.
Move relatively slowly and are very close together
14. What are some unique properties about ice that differ from liquid water or water vapor?
Ice is less dense than liquid water, so it can float on the surface of water.
15. The phase change from a solid to a liquid is called melting.
16. Describe how the structure of the molecules in a solid change as it becomes a liquid.
The molecules move faster and spread more apart. They lose their internal structure they had
as solids (this is why liquids do not have definite shape)
17. A glass of water is in the liquid phase.
18. Liquids have a definite volume but not a definite shape.
19. Describe how the molecules are arranged and moving in the liquid phase. Include a picture
with your description.
Moving faster than in solid phase and more spread out, but not as spread out as a gas
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20. In order to get liquid water to become water vapor energy must be
added to the liquid water.
21. Gases have no definite shape and no definite volume
22. Describe how the molecules are arranged and moving in the gas phase. Include a picture with
your description.
Moving faster than in a liquid and more spread out
23. The phase change from a gas back to a liquid is called condensation.
24. During this phase change energy is lost by the gas molecules as they slow down and rearrange
into liquid molecules.
25. Describe how taking a shower in a bathroom is an example of condensation.
The water vapor in the air comes in contact with the relatively colder mirror and transfer
energy to the mirror (hot to cold). The molecules lose enough energy that they change phase
into a liquid.
26. The phase change from a liquid back to solid is called freezing.
27. Dry ice turning directly into a gas is an example of what kind of phase change? sublimation
28. On a cold winter morning when you go out to a car and there is frost all over the windows
where did the ice come from?
The water vapor in the air (deposition)
29. Frost is an example of what phase change? Deposition
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Phase Change Diagram
For the above diagram, explain what is happening at each “leg”
A: Substance is only a solid. Temperature is increasing as heat energy is added
B: Melting. Substance is both solid and liquid. Temperature does not change
C: Substance is only a liquid. Temperature is increasing as heat energy is added
D: Boiling/Vaporizing. Substance is both liquid and gas. Temperature does not change
E: Substance is only a gas. Temperature is increasing as heat energy is added.
Complete the diagram below:
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