The reactivity series and extracting metals

The reactivity series lists metals from most to least reactive: potassium, sodium, lithium, calcium, magnesium, (carbon), zinc, iron, (hydrogen), copper, silver, gold. More reactive metals lose electrons more easily to form positive ions. A more reactive metal displaces a less reactive metal from a solution of its compound: iron + copper sulfate → iron sulfate + copper.

Oxidation is the gain of oxygen or the loss of electrons; reduction is the loss of oxygen or the gain of electrons (OIL RIG). Gold and silver are found as the metals themselves because they are unreactive. Metals less reactive than carbon, such as iron and zinc, are extracted by heating their oxides with carbon, which reduces them. Metals more reactive than carbon, such as aluminium, must be extracted by electrolysis, which uses much more energy.