3-D Photo of Water Molecules.

Three models for the structure of water molecules. Each individual water molecule is linked to four of its neighbors in many current models of the liquid (depicted on left). New results suggest most water molecules are linked strongly to only two others, however. This implies that liquid water molecules may be arranged in rings (middle) or chains (right) that are clustered together by additional, weaker hydrogen bonds. The oxygen atoms are shown in red and the hydrogen atoms in grey in the pictures H2O molecules.

Credit: Anders Nilsson and Hirohito Ogasawara