Learning Objective

To describe the solid, liquid and gas phases.

Water can take many forms. At low temperatures (below 0oC), it is a solid. When at "normal" temperatures (between 0oC and 100oC), it is a liquid. While at temperatures above 100oC, water is a gas (steam). The state that water is in depends upon the temperature. Each state has its own unique set of physical properties. Matter typically exists in one of three states: solid, liquid, or gas.