You will now create an outline for your final assignment.
In this lesson you learned about thermal energy and the three different ways that energy can move from one object or place to another. You learned about conduction between solid objects that are touching, about convection when liquids and gasses circulate, and about the thermal radiation of light.
You took notes on almost every page of the lesson, and now it's time to use them, as well as any other evidence presented, to write a final essay, produce a multimedia project, or create a design project in which you describe and summarize all of that heat-transfer knowledge you've collected.
If you do create a design project, you might want to choose the "Infograph It" option on the next page to do so. For your infograph you will build a hierarchy very much like the one shown in the image above, create labels for each category, and then select images of examples for specific matter categories.
Use the Arrange It drag-and-drop table activity, and complete the cards in the Organize It activity, to help organize your ideas. You can review your notes in My Work and any of the videos and glossary terms below.
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Space | Pause/Play video playback |
Enter | Pause/Play video playback |
m | Mute/Unmute video volume |
Up and Down arrows | Increase and decrease volume by 10% |
Right and Left arrows | Seek forward or backward by 5 seconds |
0-9 | Fast seek to x% of the video. |
f | Enter or exit fullscreen. (Note: To exit fullscreen in flash press the Esc key. |
c | Press c to toggle captions on or off |
Touch a freshly brewed cup of tea and what do you feel? It is hot. But the cup didn’t start out that way. This is conduction in action.
Conduction is when atoms and molecules transfer energy between themselves by colliding. The hot water molecules collide with the molecules of the cup and in a few moments, that cup is too hot to handle. This is an example of energy transfer between two different “objects” that are touching--- the water and the cup. The molecules of the two substances stay in their particular place, but the energy is transferred between the two.
Energy can also move through objects. Put a room temperature spoon in that cup, and after a few minutes, the handle of the spoon will be hot. This is also conduction. The molecules within the spoon transfer thermal energy via collisions amongst themselves.
Conduction is how solid materials transfer thermal energy between themselves and through themselves to reach a balanced state called equilibrium.
Keyboard Shortcut | Action |
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Space | Pause/Play video playback |
Enter | Pause/Play video playback |
m | Mute/Unmute video volume |
Up and Down arrows | Increase and decrease volume by 10% |
Right and Left arrows | Seek forward or backward by 5 seconds |
0-9 | Fast seek to x% of the video. |
f | Enter or exit fullscreen. (Note: To exit fullscreen in flash press the Esc key. |
c | Press c to toggle captions on or off |
Place your hand above a steaming cup of tea and what do you feel? Yep. Thermal energy, aka heat. And the reason you feel that heat is a type of energy transfer called convection.
Convection is the transfer of thermal energy through liquids and gases. You may know it better by the adage “hot air rises”, but as gas and liquids get hot, the space between molecules expands, the substance becomes less dense, and the particles rise. As they do, they lose energy (cool) and sink back down. This creates a nice circulation pattern of thermal energy.
The defining feature of convection is that energy is transferred along with the molecules. The particles don't stay put, they actually move from place to place and take their energy with them.
Convection is the way in which ice melts (air transfers heat to ice). It’s why water comes to a rolling boil (circulation of water in pot), why steam rises, and air poppers produce a perfect bowl of popcorn. Because what goes up will eventually lose thermal energy-- and must come down.
Keyboard Shortcut | Action |
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Space | Pause/Play video playback |
Enter | Pause/Play video playback |
m | Mute/Unmute video volume |
Up and Down arrows | Increase and decrease volume by 10% |
Right and Left arrows | Seek forward or backward by 5 seconds |
0-9 | Fast seek to x% of the video. |
f | Enter or exit fullscreen. (Note: To exit fullscreen in flash press the Esc key. |
c | Press c to toggle captions on or off |
Thermal energy is all about moving molecules. When molecules move, they bump and ping off of each other to transfer their energy. While they do this, they are also creating electromagnetic waves, which transfer energy outward. This transfer of heat via electromagnetic waves is called thermal radiation.
Everything-- all matter-- emits some level of thermal radiation. It is the reason a campfire glows, how microwaves heat things up, and why you show up on a thermal camera. Matter, which is hot, emits more and matter which is cold emits less. And when things are really charged up, you can feel part of the radiation as heat, but you can also see part of that radiation as visible light (ie. campfire, hot glowing poker). But all of this is the transfer of thermal energy via electromagnetic waves.
And most importantly for us here on Earth-- electromagnetic waves can travel even when there are no particles present, for instance, in the vacuum of space. They are the reason the sun's heat gets from there to here.
So go ahead and let the sunshine (aka thermal radiation) in.