Metals such as K,”Na, Ca, Mg and Al are placed above in the reactivity series. Strong reducing agent like electricity is used in the production of these metals by the electrolysis of their molten metallic compounds. Weak reducing agent such as carbon/carbon monoxide is used for the production of Zn, Fe, Ni, Sn and Pb. Copper is produced by the oxidation-reduction reactions of metal sulfide. Ag, Au, etc.
