Why does steam create pressure, yet ice expands to create water spikes?

Question

This always confuses me, is it cold that expands and heat contracts?

or the other way around, cold contracts & heat expands?

or as steam & ice spikes suggest, both steam & ice spikes expand? (free energy?)

In: Chemistry

Answer 1

Cold contracts and heat expands. As an object gets hotter, the atoms get more excited and move around more, causing expansion.

Water ice is actually an exception to the rule, normally substances are more dense in their solid phase than in their liquid phase, but ice is actually less dense than liquid water. This is because when water freezes, it creates an ordered crystal structure where the hydrogen atoms bond with the oxygen atoms in other water molecules. When they do this, the water molecules becomes further spaced apart and the density decreases. [Here’s a great picture of what I mean.](https://hi-static.z-dn.net/files/d9b/195996d71f11abd8a9b09a312247e608.jpg)