The student should have an understanding of the three states of matter and what is involved in a change of state. A good explanation of the molecular motions in the various states is found on page 324 in “Physical Science” by Ramsey, Gabriel, McGuirk, Phillips, and Watenpaugh published by Holt, Rinehart, and Winston 1986.
People in a theater are used to show the difference in molecular action between each state. I start by having people sitting in their chairs watching a performance. (solid) When the performance is over the people begin to leave their seats. (liquid) Finally, they leave the theater and head for home. (gas)
This activity gives them a better understanding of what is happening when they heat ice water to the boiling point. Plotting a graph with time vs temperature is also fun to plot and discuss.
