Science, Tech, Math › Science Congener Definition and Examples What Is a Congener? Share Flipboard Email Print The noble metals may be considered congeners. Tomihahndorf, Creative Commons License Science Chemistry Chemical Laws Basics Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated January 11, 2020 In chemistry, the term "congener" can mean different things, depending on the context. Congener Definition #1 A congener is a member of group of elements in the same periodic table group.Example: Potassium and sodium are congeners of each other. Copper, gold, and silver are congeners. Congener Definition #2 A congener can also refer to a class of compounds with similar structures and similar chemical properties. Example: The class of chemicals called polychlorinated biphenyls (PCBs) have over 200 congeners. Congener Definition #3 Congeners may refer to the oxidation states of a single element. For example, titanium dichloride (titanium 2+), titanium chloride (1+) and titanium tetrachloride (4+) are congeners. Sources Funari, Sérgio S.; Barceló, Francisca; Escribá, Pablo V. (2003). "Effects of oleic acid and its congeners, elaidic and stearic acids, on the structural properties of phosphatidylethanolamine membranes." Journal of Lipid Research. 44 (3): 567–575. doi:10.1194/jlr.m200356-jlr200IUPAC (1997). Compendium of Chemical Terminology (2nd ed.) (the "Gold Book"). Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford. ISBN 0-9678550-9-8. doi:10.1351/goldbook.