UTF-8
Heat and Temperature: An Energy View of Heating
241240246
(Note: the thermal expansion in this model is exaggerated. In reality, it is much smaller.)
1
1
org.concord.modeler.text.LineIcon750.0110101015<html>
<head>
</head>
<body marginheight="5">
<table cellpadding="0" border="0" cellspacing="0">
<tr>
<td>
<img height="58" src="motionMainIdea.png" width="98">
</td>
<td>
<font size="4" face="Verdana, Arial, Helvetica, sans-serif">When you
heat a substance, what actually happens at the atomic scale is not
just the rise of temperature (that is, atoms move faster). There are
other important changes caused by heat, such as thermal expansion
and phase change. These are all related to the change in the
internal energy of the substance.</font>
</td>
</tr>
</table>
</body>
</html>
-282012
1
1
org.concord.modeler.PageTextBox
750.0
540.0
<html>
<head>
</head>
<body face="verdana">
<map name="map">
<area coords="290,130,400,145" shape="rect" href="script:page:0:message <t><font face=verdana>The internal energy of a substance is the sum of the kinetic energy and potential energy<br>of all of its atoms.</font></t>"></area>
<area coords="420,225,480,250" shape="rect" href="script:page:0:message <t><font face=verdana>The potential energy of atoms is the energy resulting from their interactions.<br>It is often determined by the spatial arrangement of atoms.</font></t>"></area>
<area coords="310,410,440,420" shape="rect" href="script:page:0:message <t><font face=verdana>Thermal expansion is the tendency of matter to change in volume in response to<br>a change of temperature.</font></t>"></area>
<area coords="520,410,620,420" shape="rect" href="script:page:0:message <t><font face=verdana>Phase change is the change of matter from one phase to another.<br>For instance, the melting of ice is a phase change between solid<br>and liquid. The evaporation of water is a phase change between<br>liquid and gas.</font></t>"></area>
</map>
The following diagram shows what happens when you add energy to atoms. As
you move the mouse over the diagram certain terms can be clicked on. When
the mouse arrow looks like a hand click on the term and a definition will
pop up.
<p align="center" face="Verdana">
<img usemap="#map" src="heat.gif">
</p>
</body>
</html>
false
1
org.concord.modeler.PageTextBox
750.0
180.0
<html>
<head>
</head>
<body face="Verdana">
The following model shows how the average kinetic energy and potential
energy changes when we heat or cool the solid (the lattice of gray atoms).
The graph on the right shows the average kinetic energy (<font color="red">red
line</font>) and the average potential energy (<font color="blue">blue line</font>)
of the solid. The potential energy of the solid includes the energy stored
in the bonds and the van der Waals energy (think of this as the energy
stored in very small elastic rubber bands between atoms for now).
<p>
What to do: Hit the "Heat" or "Cool" button and observe what happens to
the graph on the right. Meanwhile, pay attention to how the volume of
the solid expands (note that the original surface is marked by the
dotted line).
</p>
</body>
</html>
false
1
5.0
1
org.concord.mw2d.activity.AtomContainer
Heating Substance$0.mmlfalsefalsenone
org.concord.modeler.PageXYGraph
0
Time (fs)
Kinetic Energy/Particle
Potential Energy/Particle
350
250
Time (fs)
Energy per atom (eV)
0
600
-333334
-1
false
false
Lowered Etched
5.0
1
org.concord.modeler.PageCheckBox
K. E. Shading
Redder shading means higher kinetic energy.
org.concord.mw2d.models.MolecularModel
0
K. E. Shading
org.concord.modeler.PageButton
Heat
Add heat to the solid.
false
org.concord.mw2d.models.MolecularModel
0
true
Execute MW script
org.concord.modeler.PageButton
Cool
Subtract heat from the solid.
false
org.concord.mw2d.models.MolecularModel
0
true
Execute MW script
5.0
1
org.concord.modeler.PageButton
Model snapshot
Take a snapshot of the model.
false
org.concord.mw2d.models.MolecularModel
0
Take a snapshot
org.concord.modeler.PageButton
Run
Run the simulation.
false
org.concord.mw2d.models.MolecularModel
0
true
Execute MW script
org.concord.modeler.PageButton
Stop
Stop the simulation.
false
org.concord.mw2d.models.MolecularModel
0
true
Execute MW script
org.concord.modeler.PageButton
Reset
Reset the model.
false
org.concord.mw2d.models.MolecularModel
0
true
Execute MW script
org.concord.modeler.ActivityButton
Graph snapshot
Take a snapshot of the graph.
false
Script
5.0
1
5.0
1
org.concord.modeler.PageTextBox
750.0
80.0
<html>
<head>
</head>
<body face="Verdana">
This model shows that a solid responds to heat input by increasing its
volume, which is <b>thermal expansion</b> (<a href="script:page:0:message <t><font face=verdana>Although most materials expand when heated, there are some exceptional materials that actually<br>contract within a certain temperature range. This is called <b>negative thermal expansion</b>.</font></t>">note</a><font color="gray">❏</font>),
in addition to temperature rise.
</body>
</html>
false
255 0 0
5.0
1
org.concord.modeler.ImageQuestion372300<html>
<head>
</head>
<body bgcolor="rgb(230, 230, 230)" marginwidth="5" marginheight="5" face="Arial">
<b>Take a snapshot of the model that shows thermal expansion, and then
follow the instruction below to drag in the snapshot image.</b>
</body>
</html>
false
Line
org.concord.modeler.ImageQuestion372300<html>
<head>
</head>
<body bgcolor="rgb(230, 230, 230)" marginwidth="5" marginheight="5" face="Arial">
<b>Take a snapshot of the graph that shows the increasing of energy when
heated, and then follow the instruction below to drag in the snapshot
image.</b>
</body>
</html>
false
Line
5.0
1
1
org.concord.modeler.PageTextBox
750.0
26.0
<html>
<head>
</head>
<body marginwidth="0" marginheight="0" background="topNavBarLeftMargin.jpg">
<table cellpadding="0" width="100%" border="0" id="Table_01" cellspacing="0">
<tr>
<td>
<img width="14" height="26" src="topNavBarLeftMargin.jpg">
<a href="page7.cml"><font><img width="60" border="0" height="26" src="prev.jpg">
</font></a><font><a href="page9.cml"><img width="59" border="0" height="26" src="next.jpg">
</a></font>
</td>
<td align="right">
<img width="54" height="26" src="page.jpg">
<a href="index.cml"><font><img width="46" border="0" height="26" src="index.jpg">
</font></a><a href="page1.cml"><font><img width="28" border="0" height="26" src="page1.jpg">
</font></a><font><a href="page2.cml"><img width="28" border="0" height="26" src="page2.jpg">
</a><a href="page3.cml"><img width="28" border="0" height="26" src="page3.jpg">
</a></font><a href="page4.cml"><font><img width="29" border="0" height="26" src="page4.jpg">
</font></a><a href="page5.cml"><font><img width="28" border="0" height="26" src="page5.jpg">
</font></a><a href="page6.cml"><font><img width="28" border="0" height="26" src="page6.jpg">
</font></a><font><a href="page7.cml"><img width="28" border="0" height="26" src="page7.jpg">
</a></font><a href="page8.cml"><font><img width="29" border="0" height="26" src="page8Selected.jpg">
</font></a><a href="page9.cml"><font><img width="28" border="0" height="26" src="page9.jpg">
</font></a><img width="7" height="26" src="topNavBarRightMargin.jpg">
</td>
</tr>
</table>
</body>
</html>
false