https://doi.org/10.1351/goldbook.O04363
In English is largely synonymous with @[email protected], and may be preferred when the value represents a mere parameter or number rather than being related to chemical systematics or a state of the atom in a compound. Etymologically, it stems from the no-longer-used term @[email protected] (oxidation number of a @[email protected]; the charge it would bear if all the ligands were removed along with the electron pairs that were shared with the @[email protected]) and the likewise obsolete term @[email protected] (ion charge).