It can't. Well, maybe at its triple-point, but that is another story. It is just a quirk of the language due to it being know as molten salt. For example, my

It can't. Well, maybe at its triple-point, but that is another story. It is just a quirk of the language due to it being know as molten salt. For example, my drink is full of molten water that has been frozen into cubes.