In chemistry, when two atoms share one or more pairs of electrons.
Double and triple bonds are formed if the atoms share more than two electrons, because each shared pair produces its own bond. The result is that both atoms achieve a highly stable electron configuration.
Covalent bonds are very important in organic chemistry and nanotech because of the ability of the carbon atom to form four covalent bonds. These bonds are oriented in definite directions in space, giving rise to the complex geometry of organic molecules and nanomachines. The silicon atom can also form four bonds, this is important in the production of some vec and aioid inorganic or crystalline nanostructures.