Polyatomic Ions

-ate/-ite pattern: The -ate ion has one more oxygen than -ite (e.g., sulfate SO₄²⁻ vs sulfite SO₃²⁻).
per-/-hypo- prefixes: per- means one more O than -ate; hypo- means one fewer O than -ite.
Chlorine series: ClO⁻ (hypochlorite), ClO₂⁻ (chlorite), ClO₃⁻ (chlorate), ClO₄⁻ (perchlorate).
Common cation: NH₄⁺ (ammonium) is the only common polyatomic cation.
Hydrogen prefix: Adding H increases charge by +1 (e.g., CO₃²⁻ → HCO₃⁻ = hydrogen carbonate / bicarbonate).

Must-Know Ions

Type the formula or name of each polyatomic ion. Accepts flexible formatting (e.g., SO4^2- or SO₄²⁻).

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