because the ice takes up more room than the liquid water. But, the mass has in fact stayed the same. Katie: What is this? Sorcery? Miss Roberts: No, it's because the tiny particles that make up ...

So density is mass divided by volume ... Solid ice is less dense than liquid water, because the particles must pack together more closely in the liquid. That’s why ice floats.

A team of researchers led by a physics graduate student at the University of Massachusetts Amherst recently made the surprising discovery of what they call a “shape-recovering liquid,” which defies ...