• Did you think of a question that could be studied, or make an observation that was interesting or unexpected? You should send it to the Question board!

1. Give five examples of thermal expansion in everyday life. Hint: thermal expansion effects are almost too small to see, but sometimes there are audible effects.
2. Compare the volume of liquid that a flower tube can hold, to the volume of liquid that fills the little straw that we used to make the air thermometer: approximately how many strawfuls would it take to fill the tube? This ratio gives you an idea of how much the volume of the air changes in the air thermometer. Comment on the result of your measurement.
3. Scientific theories are useful when they account for all observed facts (including facts that were not being considered when the theory was being constructed), and are able to predict the outcomes of experiments that haven't been done yet. One theory of thermal expansion that is occasionally given (by students who have heard too much about atoms without gaining much understanding of them), is that materials expand with temperature because the atoms get bigger. (The same students probably also believe that cheese is made of tangy orange atoms).

   Please discuss this theory of thermally expanding atoms. Can it describe the behavior of an iron rod? Does it apply to air? Can you use it to explain the behavior of water? What does the theory predict for sodium chloride? And finally, do we need this theory at all?

Please send us your discussions of two of these questions. Don't forget to tell us who is in the group.
If there is something that you don't understand about thermal expansion, Ask us!

This is the end of this section. (Check this box )   The next section is about thermal sensing sheets.    However, there are more activities involving thermal expansion in the manual Thermal Expansion #4 Who squoze the mustard?, and Thermal Expansion #5--#8 bimetallic coils