Why does ice float on liquid water

A single water particle (a molecule) is made up of two hydrogen atoms bonded to an oxygen atom. The oxygen will attract the negative charges in the hydrogen towards it. This will cause the oxygen atom to be negatively charged and the hydrogen atoms to become positively charged. When a liquid freezes, liquid particles move closer together and form strong bonds with one another. There are now more particles in the same area, the solid is denser than the liquid. When water freezes the negative charges on the oxygen push the particles apart. This means that the water becomes less dense with freezing.

Ice can float on liquid water because the ice is less dense so it has an ability to rise to the top of the glass of water.