UTF-8
Energy and Evaporation
204255204
What happens to the temperature when you add energy to a solid?
In this page you can experiment with two ways of adding energy.
In the first, you pound on a very hard substance with a very heavy orange hammer.
In the second, you fire energetic atoms at a crystal.
Watch carefully for changes in the substance. Can you see it melt, evaporate, or boil?
In this model, atoms are color-coded by their KE. White means low KE; red means high KE.
Each shot adds the same amount of energy to the system.
Run the experiment several times.
Count the number of shots required to make a liquid, to cause evaporation, to make a gas.
Note how much energy is required to turn all the liquid into gas.
If you look carefully, you will see boiling. This is where the material is liquid and looks a bit like Swiss cheese.
These models show that phase changes require energy.
Now, let's see how that is related to cooling by evaporation.
<Previous><Index><Next>
8.0
1
8.0
8.0
1
8.0
org.concord.modeler.text.LineIcon4010105<html><body>
<table width="100%" align="center">
<tr>
<td align="center">
<b><font size="5" face="Trebuchet MS">Energy, Boiling and Evaporation</font></b>
</td>
</tr>
</table>
</body></html>-b973747575
Trebuchet MS
8.0
1
8.0
org.concord.modeler.text.LineIcon40101010<html><body face="Trebuchet MS">
<table width="100%">
<tr>
<td width="50">
<a href="page6.cml"><img src="previous.png" border="0"></a>
</td>
<td width="50">
<a href="index.cml"><img src="index.png" border="0"></a>
</td>
<td width="50">
<a href="page8.cml"><img src="next.png" border="0"></a>
</td>
<td>
<table width="90%">
<tr>
<td width="40%" bgcolor="#f4d0b7">
Page 7 of 10
</td>
<td bgcolor="#fcf3ed">
</td>
</tr>
</table>
</td>
</tr>
</table>
</body>
</html>-6b393a7575
11
8.0
1
8.0
14
8.0
8.0
true14
8.0
8.0
14
20.0
8.0
14
20.0
8.0
14
20.0
8.0
14
146 50 50
28.0
1
8.0
1
org.concord.mw2d.activity.AtomContainer
page7$0.mml
1
1
org.concord.modeler.PageButton
Hammer
Strike the atoms
org.concord.mw2d.models.MolecularModel
0
Execute MW script
14
org.concord.modeler.PageCheckBox
Show Forces
Dotted lines represent forces that exist between neighbors
true
org.concord.mw2d.models.MolecularModel
0
Show van der Waals interactions
1
org.concord.modeler.PageTextField
West
600
20
<html>
How many hammer blows were needed to turn the solid into a liquid?
</html>
3-4
org.concord.modeler.PageTextField
West
600
20
<html>
After how many blows was some of the crystal in gas phase?
</html>
org.concord.modeler.PageTextField
West
600
20
<html>
How many blows were needed to turn all the solid into a gas?
</html>
14
14
14
14
14
14
1
org.concord.mw2d.activity.AtomContainer
page7$1.mmlfalse
org.concord.modeler.PageTextArea
200
300
<html>
Write the three most important observations here.
</html>
org.concord.modeler.ImageQuestion200300Raised Bevel
Place here a snapshot of boiling.
1
org.concord.modeler.PageButton
fire
false
org.concord.mw2d.models.MolecularModel
1
Execute MW script
org.concord.modeler.PageButton
Take a snapshot
false
org.concord.mw2d.models.MolecularModel
1
Take a snapshot
20.0
14
20.0
14
14255 0 0
1
14
1
14
page6.cml14
14
index.cml14
14
page8.cml14
14
14255 255 255