Nitrite ion
Charge: 1- · Type: Polyatomic anion · Molar mass: 46.005 g/mol
Made of: nitrogen, oxygen
How it forms
Nitrous acid loses its proton to form NO2-. Like nitrate it is stabilized by resonance, but with only two oxygen atoms it carries less oxygen and is a weaker oxidizing agent.
Naming note
NO2- is the nitrite ion; NO3- is nitrate. The -ite ending marks the ion with fewer oxygen atoms in the pair.
Examples in compounds
Sodium nitrite
Potassium nitrite
Calcium nitrite