What is the composition of a water molecule (H2O)?

A water molecule, represented chemically as H2O, is composed of two hydrogen atoms and one oxygen atom. The subscript in H2 indicates that there are two hydrogen atoms bonded to one oxygen atom. This specific arrangement is fundamental to the nature of water, making it a polar molecule, which is essential for its properties, such as solvent capabilities and high specific heat. Understanding this composition is critical in studies involving chemistry and biology, as it underpins many processes, including those relevant to bodily functions and environmental systems. The other options do not reflect the correct stoichiometry of water, contributing to misunderstandings regarding molecular structures.