Activity
American Chemical Society

Inquiry in Action: From Liquid to Gas to Solid

For Teachers 3rd - 8th
What causes frost to form on the outside of a cold container? In this activity, students will see that the liquid water can change state again and freeze to become ice.
Lesson Plan
Utah Education Network

Uen: Adding Heat

For Teachers 6th
Observe the changes in the states of matter and volume when a balloon-covered flask with water in it is heated.