Reactivity Series of Metals
Metals above carbon are extracted by electrolysis. Metals between carbon and hydrogen are extracted by reduction with carbon. Metals below hydrogen are found native.
Displacement Reactions
A more reactive metal displaces a less reactive metal from its compound.
Example: Mg + CuSO₄ → MgSO₄ + Cu (Mg is above Cu in the series)
But: Cu + MgSO₄ → No reaction (Cu is below Mg)
Think About It
Why can iron be extracted from its ore using carbon, but aluminium cannot?
Carbon is above iron in the reactivity series, so carbon can reduce iron oxide. But aluminium is above carbon, so carbon cannot reduce aluminium oxide — electrolysis is needed instead.