Michele Baggett, age 12, of Summerton, SM., for he question:

Why does ice float?

Most substances have a solid, liquid and gaseous form, depending upon the temperature. The gaseous form of water is vapor, the liquid form is wet water and the solid form is ice. The gaseous form of any substance is the most bulky, takes up most room. A puff of vapor will fill all the space it can get.

Most substances take up less space in the solid state than they do in the liquid state. But this is not true of water. When water freezes, the solid ice needs more room. Ice is a crystal, a lattice work of particles too small for our eyes to see. We think that this lattice interlocks around miniature spaces. These spaces add bulk, take up more room. In equal volumes, ice is lighter than water  which is why it floats.