Classroom Magic: Science Matters Freebies. Just remember to use the same amount of cheerios on each example. The amount of molecules doesn't change, just the amount of space in betweent them does in the different states.
Marshmallow Flight Lab: STEM Mom offers two versions of this lab, one that introduces the scientific method to students, and a second that allows students to develop an experiment on their own. FREE printable.
Every unit, there will be vocabulary words that students need to know to understand the material. I think this would be an organized foldable perfect for just that. Students could write the word on the front and write the defintion in the flap. Students could utilize this as a studying tool for the test.