Does anyone know of a simple activity or experiment for the states of water?

Question

I am currently writing a unit plan on water for first graders, and I am having tons of trouble coming up with an activity or simple experiment that has to do with the three states of water: solid, liquid and gas. All help is appreciated!

Answer 1

Boil water, creating steam, a gas
Have water in a glass, water as a liquid
Freeze water, creating an ice cube, water as a solid.

Answer 2

Simple, all you need is one ice-cube, and some time (which can be a good thing, for them to review earlier parts of the demonstration). Set out the ice-cube, as water in solid state. Wait a while (do whatever it is first graders do for thirty minutes or an hour or so) until it is melted. Then you have water in liquid form (and review that the water was previously a cube, and a solid). Wait a while longer (or you can help it evaporate with a towel) and once evaporated, you have water as a gas (and review that you previously had it as a solid and liquid).

Or you can do the same thing, but set out one ice cube an hour before you set out the other one. So you have a solid cube, a liquid state, and pretend the gas (evaporation) state.

Answer 3

A good experiment to look at how pressure can affect the states of water independent of temperature is:

Take to ice cubes and press them tightly together (the increase in pressure, without a change of temperature, causes melting).
Now set the ice cubes down, while keeping them together (the release of pressure causes the melted water to refreeze, and the two ice-cubes are now joined).

This doesn't address water as a gas though, sorry.