valence electron

noun

Chemistry.

1. an electron of an atom, located in the outermost shell valence shell of the atom, that can be transferred to or shared with another atom.

valence electron

1. An electron in one of the outer shells of an atom that can participate in forming chemical bonds with other atoms.

Word History and Origins

Origin of valence electron¹

First recorded in 1925–30

When To Use

What are valence electrons?

A valence electron is a negatively charged particle, located in the outermost shell of an atom, that can be transferred to or shared with another atom.Valence (or valency) is an atom or group of atoms’ ability to chemically unite with other atoms or groups. Electrons are negatively charged subatomic particles surrounding the nucleus of an atom in shells. Valence electrons, then, are electrons in the outermost shell of the atom that determine an atom’s or group’s ability to bond with others.In chemistry, a group refers to two or more atoms that are specifically arranged. Groups are also called radicals. Free radicals are unstable, highly reactive atoms or molecules that have unpaired valence electrons.