Chemical Bond
The attractive force that holds atoms or ions together in a stable chemical species.
Unit
kJ/mol
In depth
Bonding occurs because the combined system has lower energy than the separated atoms, the stabilisation coming from electrons being attracted to two or more nuclei at once. The three limiting types — ionic, covalent and metallic — are extremes of a continuum, and most real bonds have some character of more than one.
Examples in the real world
The ionic bond in NaCl, the covalent bonds in CH₄, and the metallic bonding that makes copper conduct and bend.