Science, Tech, Math › Science Oxyanion Definition in Chemistry Share Flipboard Email Print MOLEKUUL/SCIENCE PHOTO LIBRARY / Getty Images 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 06, 2020 An anion is an ion that carries a net negative electrical charges. Because the anions are such a large group of ions, they may be further divided according to type. One type of anion is an oxyanion or oxoanion. Oxyanion Definition An oxyanion is an anion containing oxygen. The general formula of an oxyanion is AxOyz-, where A is an element symbol, O is an oxygen atom, and x, y, and z are integer values. Most elements can form oxyanions, meeting the conditions of the octet rule. Oxyanion Examples Nitrate (NO3-), Nitrite (NO2-), sulfite (SO32-) and hypochlorite (ClO-) are all oxyanions. Source Mueller, U. (1993). Inorganic Structural Chemistry. Wiley.