Chemical bond

HomePage | Recent changes | View source | Discuss this page | Page history | Log in |

Printable version | Disclaimers | Privacy policy

In chemistry and allied sciences, chemical bond is used to describe the nature of the forces that hold atoms together in molecules or crystals.

The spatial characteristics and range of energies encompassed by these forces span a continuum, making the terms for the different types of chemical bond somewhat arbitrary or overlapping in their applicability, but the types include:

In all types of bonding, the electronic configuration of the molecule or substance (in the case of extended array structures, such as found in crystals). The types of bonding are differentiated by the extent to which electron density is localized or delocalized among the atoms of the substance. In the case of ionic bonding, electrons are more tightly associated with individual atoms, with net charges being assigned to discrete constituent atoms throughout the substance, with the nature of the interatomic (or more appropriately) interionic forces largely characterized by isotropic continuum electrostatic potentials.

In contrast, the electron density distributions within covalent bonds are not so readily assigned to individual atoms, but are instead delocalized across the molecule in structures sometimes described as molecular orbitals, which may have more directed, anisotropic properties. Intermediate situations certainly exist, with bonds having some mix of polarized ionic-like nature and some more electronically dispersed structure.

Ionic bonding can largely be described by classical mechanics, but the complexity of covalent bonding relies more heavily on concepts from quantum mechanics.

Other attractions between atoms/molecules

Other types of interatomic and intermolecular forces that occur within the chemical energy regime, but which are not characterized as bonds are:

See also: atomic orbitals, molecular orbitals, periodic table