The chemical formula for water is H₂O, which indicates that each molecule of water is composed of two hydrogen atoms bonded to one oxygen atom. This simple yet vital molecule is essential for all known forms of life. Water is polar, which contributes to its unique properties, such as high surface tension, boiling and freezing points, and its ability to dissolve many substances. These properties make water an excellent solvent and a critical component in various biological processes, including cellular respiration and photosynthesis.