In my continuing efforts to eliminate lectures from class, I decided to have the students take a modeling approach to learn the states of matter. They first started off with an PHET exploration (doc link, sim link).
After completing the exploration, I had them convene in their groups and write what defined each of the three classical states on their whiteboards. They then did a Gallery Walk, where they added a question or comment on each of the other groups boards. We got to talk about the distance between particles, their motions and how temperature affected each substances state. There were good questions about how solids can still change shape with force and about if you paused the sim, could you tell the difference between solids and liquids.
Finally we sneaked out of the class room into the old gym and played Simon Says: States of Matter. As a class they would have to act out the different states and respond when I called out a transition like, “Simon says sublime!” And at the end of the block, “Simon says condense into the classroom and then vaporize into the hallway.”