Reactivity Series

Summary: A list of metals ordered by their tendency to form positive ions. K > Na > Ca > Mg > Al > Zn > Fe > Pb > (H) > Cu > Ag > Au. Tags: igcse chemistry definition metals Created: 2026-07-14 Last Updated: 2026-07-14

The reactivity series is a listing of metals arranged in order of their tendency to lose electrons and form positive ions, from the most reactive (potassium) to the least reactive (gold): K > Na > Ca > Mg > Al > Zn > Fe > Pb > (H) > Cu > Ag > Au. The position of a metal in this series determines its chemical behaviour — metals above hydrogen react with dilute acids to produce hydrogen gas, while metals below hydrogen show no such reaction, and a more reactive metal will always displace a less reactive metal from an aqueous solution of its salt, as in the classic example Zn(s) + CuSO₄(aq) → ZnSO₄(aq) + Cu(s). The series also governs the choice of metal extraction method: metals above carbon (such as sodium, calcium, and aluminium) must be extracted by electrolysis of their molten compounds due to their high reactivity, while metals below carbon (such as iron, zinc, and lead) can be extracted by reduction with carbon or carbon monoxide in a blast furnace. Reaction with water provides an additional experimental ranking — potassium, sodium and calcium react vigorously with cold water to produce the metal hydroxide and hydrogen gas, magnesium reacts slowly with cold water but readily with steam, zinc and iron require steam to produce the metal oxide and hydrogen, and metals below hydrogen do not react with water at all. In IGCSE exams, you must be able to use the reactivity series to predict whether a displacement reaction will occur, to justify the extraction method for a given metal, and to deduce the order of reactivity from experimental observations.

This is a key term definition page — part of the IGCSE Chemistry (0620/0971) keyword glossary.