Steam
water in the gas phase, formed by the boiling of water
Steam is the name given to water when it is in a gas form. Steam is sometimes thought of as a cloud of translucent mist, however that is only the result of the steam condensing in the air, forming water vapor. Actual hot steam is invisible.

An 1817 Boulton & Watt beam engine, used in Netherton at the ironworks of M.W. Grazebrook. Re-erected on the A38(M) in Birmingham, England
When the pressure of the atmosphere is 1013 mbar (this is about the average pressure for a place which is at sea level), water will boil (turn into steam) at 100 degrees Celsius. This is the boiling point. Boiling happens in a boiler. 100 degrees Celsius is the same temperature as 212 degrees Fahrenheit, 80 degrees Réaumur and 373.15 Kelvin.
A major use of steam is to power steam engines. A steam engine is a heat engine that performs mechanical work using steam as its working fluid.
Other websitesEdit
- Steam -Citizendium