Science, Tech, Math › Science List of Common Polyatomic Ions Names, Formulas, and Charges Print oobqoo / Getty Images Science Chemistry Periodic Table Basics Chemical Laws Molecules 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. 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. Learn about our Editorial Process Updated on October 05, 2019 This is a list of some of the most common polyatomic ions. It is worth committing the polyatomic ions to memory, including their molecular formulas and ionic charge. Polyatomic Ion Charge = +1 This is the structure of an ammonium ion. Todd Helmenstine Polyatomic ions with a positive 1 charge do occur, but the main one you'll encounter and need to know is the ammonium ion. Remember, because it is a cation, when it reacts and forms a compound, it is cited first in the chemical formula. ammonium - NH4+ Polyatomic Ion Charge = -1 This is the one of the resonant structures of the chlorate anion. Ben Mills/PD Many of the common polyatomic ions have an electrical charge of -1. It's good to know these ions on sight to help balance equations and predict compound formation. acetate - C2H3O2-bicarbonate (or hydrogen carbonate) - HCO3-bisulfate (or hydrogen sulfate) - HSO4-hypochlorite - ClO-chlorate - ClO3-chlorite - ClO2-cyanate - OCN-cyanide - CN-dihydrogen phosphate - H2PO4-hydroxide - OH-nitrate - NO3-nitrite - NO2-perchlorate - ClO4-permanganate - MnO4-thiocyanate - SCN- Polyatomic Ion Charge = -2 This is the chemical structure of the thiosulfate anion. Todd Helmenstine Polyatomic ions with a minus 2 charge are also common. carbonate - CO32-chromate - CrO42-dichromate - Cr2O72-hydrogen phosphate - HPO42-peroxide - O22-sulfate - SO42-sulfite - SO32-thiosulfate - S2O32- Polyatomic Ion Charge = -3 This is the chemical structure of the phosphate anion. Todd Helmenstine Of course, several other polyatomic ions form with the negative 3 charge, but the borate and phosphate ions are the ones to memorize. borate - BO33-phosphate - PO43- Cite this Article Format mla apa chicago Your Citation Helmenstine, Anne Marie, Ph.D. "List of Common Polyatomic Ions." ThoughtCo, Aug. 28, 2020, thoughtco.com/list-of-common-polyatomic-ions-603977. Helmenstine, Anne Marie, Ph.D. (2020, August 28). List of Common Polyatomic Ions. Retrieved from https://www.thoughtco.com/list-of-common-polyatomic-ions-603977 Helmenstine, Anne Marie, Ph.D. "List of Common Polyatomic Ions." ThoughtCo. https://www.thoughtco.com/list-of-common-polyatomic-ions-603977 (accessed March 19, 2024). copy citation