Metal activity and displacement

A more reactive metal has a greater tendency to lose electrons than a less reactive metal. In an appropriate aqueous system, it can reduce ions of a less reactive metal, depositing that metal while forming its own ions. Use the supplied activity order rather than guessing from position alone. If zinc is above copper, Zn+Cu2+→Zn2++ Cu is favoured in the simple activity-series model.

Metals above hydrogen commonly react with dilute non-oxidising acids to release H2​, although oxide coatings can slow reactions. A more reactive sacrificial metal can protect iron by being oxidised instead. A barrier coating instead separates the metal from water or oxygen. Metal extraction and corrosion involve electron transfer, but observed speed also depends on conditions and protective layers.

Watch out: In this model it displaces ions of metals below it in the supplied activity series.