The formula for water is H₂O. This simple yet vital molecule consists of two hydrogen atoms covalently bonded to one oxygen atom. Water is essential for life on Earth, serving as a solvent, temperature regulator, and medium for biochemical reactions. It exists in three states—liquid, solid (ice), and gas (water vapor)—and plays a critical role in various processes, such as weather patterns and ecological systems. Water's unique properties, including its high specific heat and surface tension, make it essential for sustaining life and shaping the planet's environment.