List of Common Polyatomic Ions

Names, Formulas, and Charges

Updated on Oct 05, 2019

This is a listing of some of the most common polyatomic ions. It is worth committing the polyatomic ions to retentivity, including their molecular formulas and ionic accuse.

Polyatomic Ion Charge = +1

Ammonium ion

This is the structure of an ammonium ion. Todd Helmenstine

Polyatomic ions with a positive ane charge do occur, but the main 1 you'll run into and need to know is the ammonium ion. Call up, because it is a cation, when it reacts and forms a chemical compound, it is cited start in the chemical formula.

  • ammonium - NH4 +

Polyatomic Ion Accuse = -i

Chlorate anion

This is the i of the resonant structures of the chlorate anion. Ben Mills/PD

Many of the common polyatomic ions accept an electric charge of -1. It's good to know these ions on sight to assistance balance equations and predict compound formation.

  • acetate - C2HthreeO2 -
  • bicarbonate (or hydrogen carbonate) - HCOiii -
  • bisulfate (or hydrogen sulfate) - HSOfour -
  • hypochlorite - ClO-
  • chlorate - ClO3 -
  • chlorite - ClO2 -
  • cyanate - OCN-
  • cyanide - CN-
  • dihydrogen phosphate - HtwoPO4 -
  • hydroxide - OH-
  • nitrate - NO3 -
  • nitrite - NO2 -
  • perchlorate - ClO4 -
  • permanganate - MnO4 -
  • thiocyanate - SCN-

Polyatomic Ion Accuse = -ii

Thiosulfate anion

This is the chemical structure of the thiosulfate anion. Todd Helmenstine

Polyatomic ions with a minus 2 accuse are also common.

  • carbonate - COiii two-
  • chromate - CrO4 ii-
  • dichromate - Cr2Ovii ii-
  • hydrogen phosphate - HPO4 2-
  • peroxide - O2 2-
  • sulfate - And soiv 2-
  • sulfite - And so3 two-
  • thiosulfate - Due south2O3 2-

Polyatomic Ion Charge = -3

Phosphate anion

This is the chemic structure of the phosphate anion. Todd Helmenstine

Of course, several other polyatomic ions form with the negative iii charge, just the borate and phosphate ions are the ones to memorize.

  • borate - BO3 three-
  • phosphate - POiv three-