Common Polyatomic Ions

Polyatomic Ions Definition and Fundamentals

• A polyatomic ion is defined as a group of covalently bound atoms that acts as a single unit carrying an overall electrical charge.
• Unlike monatomic ions which consist of a single charged atom, polyatomic ions consist of multiple atoms bonded together that collectively carry a net positive or net negative charge.
• There is no single shortcut or easy system to automatically derive the names of polyatomic ions; memorization of the most common polyatomic ions, their chemical formulas, and their net charges is essential for mastering chemical nomenclature.

Reference Table of Common Polyatomic Ions

• Ammonium Ion:

  • Chemical Formula: $NH_4^+$
  • Net Charge: $+1$
  • Ion Type: Cation
  • Atomic Composition: One nitrogen atom covalently bonded to four hydrogen atoms.

• Nitrate Ion:

  • Chemical Formula: $NO_3^-$
  • Net Charge: $-1$
  • Ion Type: Oxyanion
  • Atomic Composition: One nitrogen atom bonded to three oxygen atoms.

• Sulfate Ion:

  • Chemical Formula: $SO_4^{2-}$
  • Net Charge: $-2$
  • Ion Type: Oxyanion
  • Atomic Composition: One sulfur atom bonded to four oxygen atoms.

• Carbonate Ion:

  • Chemical Formula: $CO_3^{2-}$
  • Net Charge: $-2$
  • Ion Type: Oxyanion
  • Atomic Composition: One carbon atom bonded to three oxygen atoms.

• Phosphate Ion:

  • Chemical Formula: $PO_4^{3-}$
  • Net Charge: $-3$
  • Ion Type: Oxyanion
  • Atomic Composition: One phosphorus atom bonded to four oxygen atoms.

• Chlorate Ion:

  • Chemical Formula: $ClO_3^-$
  • Net Charge: $-1$
  • Ion Type: Oxyanion
  • Atomic Composition: One chlorine atom bonded to three oxygen atoms.

Course Assignment Information

• Platform: Mastering Chemistry
• Module: Homework Chapter 06
• Item Number: Item 12