18-VE rule (18-valence-electron)

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• Valence electron — In chemistry, valence electrons are the electrons contained in the outermost, or valence , electron shell of an atom. Valence electrons are important in determining how an element reacts chemically with other elements: The fewer valence electrons …   Wikipedia

• Electron counting — is a formalism used for classifying compounds and for explaining or predicting electronic structure and bonding. Many rules in chemistry rely on electron counting:*Octet rule for main group elements, especially the lighter ones such as carbon,… …   Wikipedia

• Electron configuration — Electron atomic and molecular orbitals Simp …   Wikipedia

• Electron shell — Periodic table with electron shells An electron shell may be thought of as an orbit followed by electrons around an atom s nucleus. The closest shell to the nucleus is called the 1 shell (also called K shell ), followed by the 2 shell (or L shell …   Wikipedia

• Valence (chemistry) — For other uses, see Valence (disambiguation). In chemistry, valence, also known as valency or valence number, is a measure of the number of bonds formed by an atom of a given element. Valence can be defined as the number of valence bonds[1] a… …   Wikipedia

• Valence bond theory — In chemistry, valence bond theory explains the nature of a chemical bond in a molecule in terms of atomic valencies. [Murrel, JN, Kettle, SF Tedder, JM The Chemical Bond , John Wiley Sons (1985) ISBN 0 471 90759 6] Valence bond theory summarizes… …   Wikipedia

• rule — A criterion, standard, or guide governing a procedure, arrangement, action, etc. SEE ALSO: law, principle, theorem. [O. Fr. reule, fr. L. regula, a guide, pattern] Abegg r. the tendency of the sum of the …   Medical dictionary

• Electron mobility — This article is about the mobility for electrons and holes in metals and semiconductors. For the general concept, see Electrical mobility. In solid state physics, the electron mobility characterizes how quickly an electron can move through a… …   Wikipedia

• 18-Electron rule — The 18 electron rule is a rule of thumb used primarily in transition metal chemistry for characterizing and predicting the stability of metal complexes. Valence shells of a transition metal can accommodate 18 electrons: 2 in each of the five d… …   Wikipedia

• d electron count — The d electron count is a chemistry formalism used to describe the electron configuration of the valence electrons of a transition metal center in a coordination complex.[1][2] The d electron count is an effective way to understand the geometry… …   Wikipedia

• Polyhedral skeletal electron pair theory — In chemistry the polyhedral skeletal electron pair theory provides electron counting rules useful for predicting the structures of clusters such as borane and carborane clusters. The electron counting rules were originally formulated by Kenneth… …   Wikipedia