Question

Why does ice float on water ?

Answer 1

The density of water is approx. one gram per cubic centimeter. It is dependent on its temperature but the relation is not linear. When cooled from room temperature liquid water becomes dense but at 4 degree Celsius pure water reaches its maximum density. As it is cooled it expands to become less dense. So the layer of ice floats on water as insulating layer. The warm layer settles at the bottom in winters.