Water. Image 2 of 3. Artwork of water molecules in the liquid state. The atoms are shown as balls here, and are colour coded: oxygen (red) and hydrogen (yellow). Water has the formula H2O, with each oxygen atom bonded to two hydrogen atoms. In liquid water, the molecules are closely spaced but with a random arrangement. For water as a solid (ice) and as it evaporates, see images A504/087 and A504/089 respectively.