This document discusses various properties of water. It describes how water occurs naturally in solid, liquid, and gas states on Earth's surface and in the human body. Water is colorless, odorless, and tasteless, boils at 100 degrees Celsius and freezes at 0 degrees. As a universal solvent, water conducts heat and electricity well. Chemically, water decomposes slightly above 200 degrees and acts as a solvent in many reactions, such as synthesizing hydrochloric acid. Alkali metals like potassium, sodium and calcium react vigorously with water and produce flames of different colors. The document also examines the reactions of boiling water and steam with various metals.