Where does it go? This is a watching kind of activity. Your teacher will heat a pyrex cooking container on a hot plate or stove burner. Students need to sort of "hunker" down to see the water from the side, rather than from the top of the container.

Soon, the water will boil. There is a saying that "A watched pot never boils," but that is really not true. It just seems to take a longer time if you are watching it than if you do something else while waiting for it to boil. However, we need to watch the water, and remember what it looks like as it heats and as it comes to a boil.

How can you tell when it's boiling? There will be large bubbles that travel from the bottom of the pot, through the water, to the surface of the water, where the bubbles burst. It looks a little like a storm at sea.

Look into the air above the container, again, looking from the side; not from the top of the pot.

Do you see small drops of water in the air above the pot?

There appears to be an area between the bottom of the lowest drops and the surface of the water. How can that be? We all know that what goes up has to come down, and we all know that what goes up has to get there--it just doesn't be up without doing some traveling. Why can't we see the drops traveling?

The brilliant scientist tells us that the heated water particles are too small to be seen just as they leave the surface of the water. After they get a bit above the very hot place over the surface of the water, the tiny drops cool a little and join with other tiny drops, to form drops that are large enough to see.

We have now learned something about water particles, heat, cooling, and what else?