As the water enters the space inside the can, it pushes the air which was there out, since they both cannot take up the same space at the same time. Put the bottle in the freezer until the contents are frozen. The ice will expand, pushing the top off. The molecules in ice have a different configuration than the molecules in water. Have students watch what happens to the water line as the ice melts.
Closure Discuss the experiment hypotheses, results, and conclusions.
Examine the team charts to make certain that all the teams got the same measurements for the first step of each part of the experiment. The experiment results will be affected if the measurements weren't properly taken. Discuss the fact that the solids and liquids were carefully measured, but there was no way to carefully measure gas, so that the experiment cannot fully compare a gas with the liquid and solid. To view the activity sheets, you need Adobe Acrobat Reader. Click here to download Acrobat Reader, complete with plug-ins for your browser.