There are several topics being covered in this lesson (lab). The students will receive either moth flakes or moth nuggets. They will chart the freezing of these substances and compare their data with other groups. By creating a graph, students will learn that while a substance is going through a phase change, the temperature of that substance will not change. That is the primary goal of the lesson. Secondary to that is the fact that different substances freeze/melt and vaporize/condense at different temperatures. This illustrates that phase changes are characteristic properties and can help to identify substances as being different from each other. All of the moth flake people will discover that they freeze at the same temperature and the moth nugget people will discover that they freeze at the same temperature. When the students graph the data they will see that while the substances are freezing, the temperature is remaining constant.
McKinney, Jeff, "Moth Flakes or Moth Nuggets" (2006). Lesson Plans. 135.