a chemical bonding of two hydrogen atoms with an oxygen atom

a grouping of two atoms of hydrogen and one atom of oxygen

an example of the single covalent bond between oxygen and hydrogen

a relatively simple affair, one oxygen atom attached to two hydrogen atoms governed by well understood equations of atomic physics

a tiny electric dipole

The smallest unit of water; consists of two hydrogen atoms and an oxygen atom.

A molecule, consisting of one central oxygen atom and two hydrogen atoms along an angle of 104°, forming an electrostatic dipole because of the asymmetric distribution of charge. The dipole results in a high dielectric constant for water, whether in vapor, liquid, or solid form. Resonances in the intermolecular bonds result in absorption and emission of electromagnetic radiation at near- and thermal-infrared wavelengths, hence the importance of water vapor in the greenhouse effect in the atmosphere and water substance as precipitation in the scattering and absorption of radar waves.