Why does water expand when frozen whilst other liquids contract?
In: 9
When most things freeze, they go from a random arrangement of molecules/atoms to a crystal, which has a regular arrangement of molecules/atoms in a rigid framework.
In almost all materials, the solid crystal is more compact than the liquid arrangement, hence most materials shrink when they freeze.
Water, due to a fairly unique molecular shape and charge (it’s a compact, polar, and “bent” molecule), has a crystal structure that pushes the molecules a little farther apart than they are on average when they’re a liquid. Hence expansion on freezing.
Tl;dr: Water has a fairly unique molecular structure that results in the solid crystal being slightly less dense than the liquid form.
Latest Answers