Why Does Ice Float in Water?

Like most substances, water is made up of many small particles called molecules. In water they are packed tightly together. The molecules in ice are not packed so tightly. Even though they take up more space they are lighter. Since ice is lighter than water, it floats. When most substances are changed from a liquid state or gas to a solid state, the volume becomes smaller. But when water is turned into a solid in the from of ice its volume increases. This is because the hydrogen atoms of water molecules push apart from each other as the water turns from a liquid state into ice. Because the molecules in ice are less densely packed than the ones in water, ice floats.