Skip to main content


Updated Monday, 26th September 2005

We explain how water changes state into steam

This page was published over 16 years ago. Please be aware that due to the passage of time, the information provided on this page may be out of date or otherwise inaccurate, and any views or opinions expressed may no longer be relevant. Some technical elements such as audio-visual and interactive media may no longer work. For more detail, see our Archive and Deletion Policy.

When water converts into steam it does so at its boiling point.

At sea level water boils at 100 degrees Celsius, but this can vary depending on altitude and air pressure.

Norris Geyser basin, Yellowstone [Image: Gouldy99 under CC-BY-NC-ND licence]
Steam rising from the Norris Geyser Basin, Yellowstone Park [Image: Gouldy99 under CC-BY-NC-ND licence]

The high boiling point of water is also a result of hydrogen bonding - extra heat must be used to disrupt the bonds.

Without these bonds water would boil at about -80 degrees Celsius. The attractive forces in steam are much weaker than those of liquid water.

The molecules move more quickly than in liquid water, are widely separated and they can move around in any direction.


Become an OU student


Ratings & Comments

Share this free course

Copyright information

Skip Rate and Review

For further information, take a look at our frequently asked questions which may give you the support you need.

Have a question?