1One trick water can do
Water can hide — then come back
You only need two ideas. Watch each one happen:
Hot water spreads out
Heat flings the water bits far apart until they fly off as a gas. They're so spread out your eyes can't catch them — the water is still there, just invisible.
Cool air clumps it back
When the gas cools, the bits slow and crowd together into tiny droplets you can see — a little cloud. Cooling is what makes the water show up again.
2Two looks, same water
The clear gap vs the white cloud
Above a boiling spout there are really two zones. Same water — but they look completely different because of how hot and spread out the water is:
The clear gap
Right at the spout the water is a super-hot gas, flung so wide apart it's totally invisible.
The white cloud
A bit higher up it has cooled and clumped into tiny drops — now you can finally see it.
3Your turn — turn up the heat
Make it boil and watch the plume
Drag the heat up and down. Watch the invisible gas pour out of the clear gap at the spout, then turn into the white cloud a little higher up where the room air cools it.
4Try a new temperature
What if the plate is hotter than the steam?
In this pretend lab, the clear gap contains water vapor at 100°C. A heater keeps a dry plate at 110°C. Predict what happens when that hotter plate enters the gap.
Predict before you test
The plate stays at 110°C in the 100°C water vapor. Will liquid drops grow on it?