Polyatomic ion

A polyatomic ion is a group of atoms bound together, with a net positive or negative electrical charge. See molecule.

Examples of polyatomic ions are:

• Acetate (CH₃COO^-) colorless
• Ammonium (NH₄⁺) colorless
• Carbonate (CO₃^2-) colorless
• Chlorate (ClO₃^-) colorless
• Chlorite (ClO₂^2-) colorless
• Chromate (CrO₄^2-) yellow
• Cyanide (CN^-) colorless
• Dichromate (Cr₂O₇^-) red
• Hydronium (H₃O⁺) colorless
• Hydroxide (OH^-) colorless
• Nitrate (NO₃^-) colorless
• Nitrite (NO₂^-) colorless
• Phosphate (PO₄^3-) colorless
• Sulfate (SO₄^2-) colorless
• Sulfite (SO₃^2-) colorless