Using this resource, students understand that particle movement changes as a substance changes from one phase to another phase. This lesson is designed to give students the opportunity to observe a phenomenon created by particle movement. Students begin to move from the fundamental concept of solid, liquid and gas to the reasoning for why the states exist under given conditions. Emphasis needs to be placed on helping students understand that there are different motions exhibited by substances in their respective phases. As temperature increases, particle movement increases. When the temperature reaches a certain level the substance is able to change phase and becomes a liquid. When this continues, the substance will once again change phase and becomes a gas or vapor. (author/kct)

Although this site is designed for elementary and middle school students, there is a distinct use for higher grades particularly in the areas of HVAC and electricity/electronics which address matter in its various states. High school teachers who utilize this plan, should concentrate on the "Extensions" section, encouraging students to observe molecular motion and energy transformation as it might apply to the context of refrigeration and heating. A teacher using this site would find many other useful sites related to the industrial and engineering context.