The octet rule in chemistry is the principle that bonded atoms share their eight outer electrons. This gives the atom a valence shell resembling that of a noble gas. The octet rule is a "rule" that is sometimes broken. However, it applies to carbon, nitrogen, oxygen, the halogens, and most metals, especially the alkali metals and alkaline earths.
A Lewis electron dot diagram may be drawn to illustrate the octet rule. In such a structure, electrons shared in a covalent bond between two atoms are counted twice (once for each atom). Other electrons are counted once.
Sources
- Abegg, R. (1904). "Die Valenz und das periodische System. Versuch einer Theorie der Molekularverbindungen (Valency and the periodic system – Attempt at a theory of molecular compounds)". Zeitschrift für anorganische Chemie. 39 (1): 330–380. doi:10.1002/zaac.19040390125
- Langmuir, Irving (1919). "The Arrangement of Electrons in Atoms and Molecules". Journal of the American Chemical Society. 41 (6): 868–934. doi:10.1021/ja02227a002
- Lewis, Gilbert N. (1916). "The Atom and the Molecule". Journal of the American Chemical Society. 38 (4): 762–785. doi:10.1021/ja02261a002