When water becomes steam
Heating water can make a gas that carries energy.

Picture in words: 1. Add heat: Energy enters liquid water and its molecules move more vigorously.
2. Boil: At the boiling point for the local pressure, vapour bubbles form within the liquid.
3. Do work: In machinery, pressurized steam can move a piston or spin a turbine.
4. Cool: Water vapour can condense into liquid and transfer heat to its surroundings.

One more wonder: Pure water vapour is invisible. The white mist above a kettle is tiny liquid droplets.
Read or draw this lesson. Do not experiment with boiling water, steam or sealed containers; they can cause serious burns.

Question: What is the white mist you can see above hot water?
Answer: Tiny liquid droplets

Sources:
STEAM Museum: how an engine works — https://www.steam-museum.org.uk/wp-content/uploads/2021/05/STEAM_Education_Pack_4___Activity_Sheets_to_use_before_during_and_after_your_visit-2.pdf
EIA Energy Kids: forms of energy — https://www.eia.gov/kids/what-is-energy/forms-of-energy.php

Reviewed 28 September 2026. Simplified educational illustration, not to scale.
https://atherverse.com/kids/how-things-work/steam/