1. Conduction Investigation 4, Part 2
Heat Transfer
Conduction
Investigation 4, Part 2
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2. Notebook Answer the following questions on LOLs:
What is radiant energy?
How does radiation affect the surface of Earth?
Energy that passes through space
Earth receives energy from the Sun
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3. Visible Light Main kind of energy from the Sun that heats the Earth
Energy is transferred when:
light energy is absorbed by molecules in Earth’s surface
causing them to move faster, which increases the temperature
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4. Heat Transfer Walking barefoot on a hot day - What did you feel? Why?
How did heat transfer from the cement to your feet?
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5. Challenge: Science Buddies
Heat cold water to about 30˚C without mixing the hot and cold water.
Using a cup, cylinder, and two thermometers.
How would you set up the experiment?
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6. The Results
Were you able to raise the temperature of the cold water to 30˚C?
How did heat transfer from the hot to cold water?
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7. The Explanation No cold, only heat Cold is actually low levels of heat
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Heat energy goes out of your hand into the ice cube

8. Heat Motion of atoms and molecules Greater motion = more heat energy
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9. Conduction
Energy transfer happens between molecules or atoms when they come in contact
Faster moving molecules in the hand bump into the slower moving molecules in the ice
Molecules in hand slow down and we feel it as cold
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10. Multimedia Watch the animation of solids, liquids, and gases.
Watch the animation on conduction.
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CD-ROM Molecules in Solids, Liquids,and Gases ( Matter and Energy section).

11. Heat Conduction Responses
Complete the “Heat Conduction” worksheet on page 17 of your lab book.
BREAKPOINT
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Student Lab Notebooks P. 17

12. Key Points
Remember: when two materials at different temperatures make contact, energy transfers from the hotter material to the colder material.
As materials gain heat energy, the motion of their atoms and molecules increases.
Molecular Motion = Heat
View  Thermometer Animation on FOSSWEB
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13. Pot of Soup Why is the metal spoon hot?
Were you surprised to find that it was hot?
How did the spoon handle get so hot?
Spoon handle hadn’t been in the soup
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14. Can Heat Conduct through an Object?
Materials
P. 19 of Lab Notebook
Aluminum and steel bars
Temperature strips
Plastic-foam cups
Large plastic cups
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15. Temperature Strips Liquid-crystal temperature strips
Crystals inside turn colors when they reach a given temperature
Different crystals produce their colors at different temperatures
No color is temperature is below 30˚C or above 36˚C
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16. The Results
The temperature strips displayed color after the metal had been in the hot water for awhile. Color indicates the temperature went up.
Heat energy in hot water molecules transferred to metal molecules, making them move more.
Both conduct heat, Aluminum conducts better, since the heat moved up the bar faster.
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Student Lab Notebooks P. 19

17. Conduction
Energy transfer happens between molecules or atoms when they come in contact
Faster moving molecules in the hand bump into the slower moving molecules in the ice
Molecules in hand slow down and we feel it as cold
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Student Lab Notebooks P. 19

18. How do you think….
The Sun shines on Earth and the air gets warm. How do you think that happens?
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Student Lab Notebooks P. 19

19. How it happens…. Radiant energy strikes Earth’s surface
The surface absorbs the energy
Surface molecules increase their motion
Molecules of air touches the heated surface of Earth
Energy is transferred from surface to the air
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20. Another energy transfer
There is a more important way that heat energy enters the atmosphere…
Reradiation
Another way heat energy enters the atmosphere
Matter radiates heat and distributes it into the atmosphere
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21. Reradiation All matter radiates energy
Hot matter radiates more energy than cold
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22. Reradiation Think back to your earth materials investigation.
Sand, soil, water, & air absorbed energy from the Sun which made them warm up.
When we moved them to shade, they cooled down
Reradiated energy that was absorbed to the air
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23. What happens to the reradiated energy?
Most reradiated energy is not visible, it is infrared (heat) C O
Infrared energy
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Then transfers the energy to N2 and O2 in the atmosphere

24. Reading Read “Heating the Atmosphere” starting on page 22.
With a partner answer the “Think Questions” on page 26 or complete 6 ? summary.
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Student Resource Book P.22-26