Why does water expand on freezing?
Water molecules are rather special. They are called polar molecules. This gives a suggestion that when allowed to slow down and get together, their congregation would not be amorphous. (Just think of human beings packed together). The result is that at freezing temperature they form structures. We call these structures crystals. Crystals are like houses, made of molecules. Before freezing, the molecules could be together in any formlike piles of small bricks or stones.
Related Questions
- Because you insisted that the container be unbreakable (and, I presume, won expand either), I won go into detail on just how much pressure water exerts during its expansion while freezing. Just recall that ice can break steel ship hulls with no problem.
- Why is the electrolysis of water classified as a chemical change but the freezing of water is not?
- How can freezing water expand, even bursting metal pipes, with no energy input to explain it?
