Matter exists in three states—solid, liquid, and gas. Even Kevin knows that one! And of all the matter on the planet, water is the most likely to be spotted in all three; y’know, water, ice, and steam/fog. (When was the last time you saw, say, granite in its gaseous form?)
The difference between the physical properties of water in its three states are pretty significant, and worth noting. Steam’s a little hard to work with, so this handy dandy Demo Science science demo will focus solely on its liquid and solid forms. Read on for science!
Chill Out, Man!
For this one, you’ll need a small jar, water, a piece of cardboard slightly larger than the top of said jar, and a freezer. Fill your jar to the tippy tip top with water, then carefully place it in the freezer. Cover the top of the jar with the cardboard.
Then just hang out and wait for it to completely freeze. Not a terribly involved experiment, really. Maybe spend the freezing time playing Monopoly. (Keep an eye on Kevin—that punk cheats!)
So, once your water’s good and frozen, take the jar out of the freezer and have your students (or whomever you’re doing this demonstration for) observe what has become of it.
More Volume Bang for the Frozen Buck
Observant students—by which I mean any students with functioning eyeballs—will notice that the cardboard “lid” is lifted well above the top of the jar on top of the water that is now ice. This is because, as water freezes, it expands so as to create more space for its molecules to spread out. It’s actually the same process water goes through as it transitions into steam via heat, but in that case the molecules just keep spreading out and dissipate into the atmosphere.
Because there’s nowhere for it to go inside the jar (glass is stronger than water, in this case), the water expands upward as it becomes ice. Had you sealed the jar securely with a screw-on lid, the expanding ice would have broken the jar in order to make room. This is the same basic process that causes water pipes to break in the dead of winter, which is—always—coming.