1) Theoretical chemistry 
nonbonding pair; unshared pair. Electrons that are not involved in bonding.
In chemistry, a lone pair is a valence electron pair which is not shared with another atom and is sometimes called a non-bonding pair. Lone pairs are found in the outermost electron shell of atoms. They can be identified by using a Lewis structure. Electron pairs are therefore considered lone pairs if two electrons are paired but are not used in c...
(from the article `chemical bonding`) ...the Lewis structure of hydrogen chloride is denoted HCl:.... . The electron pair represented by the line is called a bonding pair; the three other ... ...proposed. One that fits into the general scheme of this article is to think of the AH unit as being composed of an A atomic orbital and a hydro...
A pair of electrons not involved in bond formation.
Pair of electrons residing on one atom and not shared by other atoms; unshared pair.
Pair of electrons residing on one atom and not shared by other atoms, unshared pair.
A pair of electrons not involved in bond formation.
(Learning Modules / Chemistry / Polymers) A pair of electrons in an atom which are not involved in bonding.
In chemistry, a pair of electrons in the outermost shell of an atom that are not used in bonding. In certain circumstances, they will allow the atom to bond with atoms, ions, or molecules (such as boron trifluoride, BF3) that are deficient in electrons, forming coordinate covalent (dative) bonds in which they provide both of ...