Does ice weigh more than water?

In general, if ice and water have the same volume, then the ice weighs less. This is because ice is less dense than water and occupies more space. Therefore, a gallon of ice weighs less than a gallon of water.

When water freezes into ice, the individual water molecules expand to occupy more space, increasing in volume by about 9 percent. As the liquid turns into a crystalline solid, the water molecules stay expanded and mesh together to form a solid. Due to this phenomenon, the same volume of ice and water have different masses and different densities. For this reason, ice floats in water.