Term: active state https://doi.org/10.1351/goldbook.A00111 Definition: corrosion in the active state occurs by direct transfer (which may involve one or several steps) of metal ions from the metallic phase to the adjacent electrolyte. The corrosion current of an active metal usually increases when the electrode potential is made more positive, other conditions remaining constant. Related Terms: 1) corrosion (http://doi.org/10.1351/goldbook.C01351). 2) corrosion current (http://doi.org/10.1351/goldbook.C01354). 3) electrode potential (http://doi.org/10.1351/goldbook.E01956). Source: PAC, 1989, 61, 19. 'Electrochemical corrosion nomenclature (Recommendations 1988)' on page 21 (https://doi.org/10.1351/pac198961010019) Citation: 'active state' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.A00111 License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms. Disclaimer: The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.