Cambridge IGCSE Chemistry · Syllabus 0620 · Acids, Bases and Salts
Spectator ion
What is Spectator ion?
An ion that is present in the solution before and after a reaction in exactly the same form, taking no part in the change. Spectator ions are cancelled from both sides of a full ionic equation to leave the net ionic equation.
This definition is part of the Acids, Bases and Salts chapter in Cambridge IGCSE Chemistry.