Water is an example of matter that exists in three states: as a gas over 100°C, as a liquid between 1-99°C, and as a solid below 0°C. It is made of hydrogen and oxygen, has volume and mass, and is odorless, colorless, and tasteless. Water changes state through heating and cooling, melting when heated as a solid, evaporating when heated as a liquid, freezing when cooled as a liquid, and condensing when cooled as a gas.