Definition of Stock system
: a system in chemical nomenclature and notation of indicating the oxidation state of the significant element in a compound or ion by means of a Roman numeral that is used in parentheses after the name or part of the name designating this element and ending invariably in -ate in the case of an anion and that is placed above and to the right of the symbol for this element
- according to the Stock system nitrous oxide is named nitrogen (I) oxide, ferrosoferric oxide Fe3O4 is iron (II, III) oxide FeIIFeIII2O4, and potassium manganite is potassium manganate (IV) K2MnIVO3
