Skip to content
Science, Maths & Technology


Updated Monday, 26th September 2005

From water into ice, just how does it change state?

This page was published over five 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 Please be aware that due to the passage of time, the information provided on this page may be out of date or otherwise inaccurate, and any views or opinions expressed may no longer be relevant.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 ice it does so at its freezing point.

At sea level water freezes at 0 degrees Celsius, but this can vary depending on altitude and air pressure.

Ice melting [Image: suburbanslice under CC-BY-NC-ND licence] Creative commons image Icon SuburbanSlice via Flickr under Creative-Commons license
Ice melting [Image: suburbanslice under CC-BY-NC-ND licence]

At its freezing point, water becomes solid ice. As water cools, the molecules lose kinetic energy and start to slow down.

The hydrogen bonds hold the molecules together in a regular lattice, and the solid state is formed.

Because the molecules are close to each other and bound together tightly, ice has a defined volume and shape, both characteristic features of solids.

Most natural ice has a hexagonal structure, with each molecule bonding to four others.

Unlike most solid forms of liquids, ice is less dense than liquid water.

This is because, in ice, the hydrogen bonds hold the molecules in a lattice structure, where the distance between each molecule is greater than in liquid water.

The lower density of ice means that it floats in water.





Related content (tags)

Copyright information

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

Have a question?