The principal reason it transforms is that water is a collection of molecules, H2O, every child learns that.And that bond has the property that as the bonds get stronger when you cool water, the ice expands.
Ira FlatowI love ice, when I was in Antarctica many decades ago, I got to see a lot of ice. And the one thing that impressed me -because I love to talk about ice - is that it has a color.
Ira FlatowH2O it's a complicated, three-dimensional, charged object. And one can pack these things in many different ways, a little like playing the child's game of jacks, where those complicated little objects can be thrown together in all different ways.
Ira FlatowIce is remarkable in many ways. A simple experiment one can do at home is to add salt to an amount of water in different concentrations. For example, one can mimic the concentration of the ocean, or one can make it even saltier.
Ira Flatow