Water is the ubiquitous chemical substance, composed of hydrogen and oxygen, that is essential for the survival of many known forms of life. In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor or steam
Water is the chemical substance with chemical formula H2O: one molecule of water has two hydrogen atoms covalently bonded to a single oxygen atom. Model of hydrogen bonds between molecules of water
Water in three states: liquid, solid (ice), and (invisible) water vapor in the air. Clouds are the accumulations of the droplets, condensed from vapor-saturated air.