1) High reactivity of metals – the metals which are highly reactive are easily oxidized since they can easily donate electrons and can also form oxides.
2) Presence of moisture and air – oxidation increases in the presence of moisture and air since moisture acts as a solvent for oxygen in air and thus furnish the electrolyte needed for the reaction.More is the air; more oxygen is circulated on the substance to be oxidized.
3) Presence of impurities- Presence of impurities increases the rate of oxidation since their presence creates anodic and cathodic areas in the object to be oxidized.Thus, tiny electrochemical cells are formed at the exposed part of the impurities and the object (metal) is oxidized easily.
4) Metals or Stains- Oxidation leads to discoloring of metals or staining of metals. Different metals show different coloured stains.Example : copper looks green when oxidized.
5) Presence of electrolyte- saline water- The presence of saline water increases oxidation since saline water contains acidic slats which provide H+ ion which in turn increase the rate of oxidation.