Provisional Recommendations are drafts of IUPAC recommendations on terminology, nomenclature, and symbols, made widely available to allow interested parties to comment before the recommendations are finally revised and published in IUPAC’s journal Pure and Applied Chemistry.
Provisional Recommendations Abstract:
In one of many uses of the chemical term valence, it means a quantity that characterizes the bonding situation of an atom. Historically, the definition of the valence quantity has varied across different branches of chemistry. Based on our analysis of the use of this quantity, we recommend limiting the definitions to two contexts; the noun valence as the number of two-electron bonds associated with an atom, and the adjective n-valent for the oxidation state of a metal, which cover the past 70 years.
Keywords: bond order; bond valence; Lewis formula; valence; valence electrons
> Access full text – return comments to the corresponding authors: Pavel Karen pavel.karen@kjemi.uio.no
Comments by 30 Nov 2026