Shaving Cream Storminess
This is an excellent modeling activity where, in Part 1, students make a model of the atmosphere where water represents air, shaving cream represents clouds, and food coloring represents rain. Along the way, the formation of clouds by condensation of water vapor into drops, and the falling of these drops under the pull of gravity is explored.
In part 2, students make some artificial snow using a combination of shaving cream and cornstarch. Snow forms within clouds when ice crystals stick together in the process of forming snow flakes. When the flakes become heavy enough they too start falling to the ground under the pull of gravity.