The water molecule is a simple inorganic molecule, but water plays a critical part in life's functions. The hydrogen and oxygen atoms of water are joined by polarized covalent bonds. The polarization of the molecule allows water molecules to enter hydrogen bonds with other water moecules and with other polarized molecules. Hydrogen bonds are weak electrostatic bonds. The negatively charged oxygen or nitrogen forms a hydrogen bond with a hydrogen on another molecule, or another region of the same molecule.
Hydrogen bonds form 'bridges' that stabilize large molecules.
In water, hydrogen bonds between water molecules account for many of the peculiar characteristics of water. Each water molecule can be involved in up to four hydrogen bonds. Water molecules, through their hydrogen bonds, show cohesion . One effect of cohesion is the surface tension that allows water droplets to 'bead up'. A second effect of hydrogen bonding is the special nature of ice.