What is the chemical formula for water?

The chemical formula for water is represented as H₂O. This indicates that each molecule of water consists of two hydrogen atoms covalently bonded to one oxygen atom. The simplicity of this formula highlights the essential composition of water, which is vital for numerous biological and chemical processes.

In contrast, H₂O₂, known as hydrogen peroxide, contains an additional oxygen atom and has very different properties, making it a powerful oxidizing agent rather than a life-sustaining substance like water. HO, while representing a hydroxyl group, does not accurately depict the molecular structure of water since it implies an incomplete molecular representation. Finally, H₂O₃, which appears as ozone with two additional oxygen atoms, is not a stable chemical entity and thus does not represent water at all. Therefore, the formulation H₂O is recognized as the universally accepted representation of water's molecular composition.