The chemical symbol for water is H₂O, indicating that each molecule of water is composed of two hydrogen atoms (H) and one oxygen atom (O). This simple yet crucial compound is essential for life and plays a vital role in various biological, chemical, and physical processes on Earth. Water serves as a solvent, a means of transportation for nutrients and waste in organisms, and is integral to many ecological systems. Its unique properties, such as high surface tension and ability to exist in three states (solid, liquid, gas), make it a unique and indispensable resource.