Oxidation is a chemical process by which metals or compounds are combusted leading to formation of either an oxide ,or a reduced stage.This means increase or decrease in valency charged ion of the metal.Example, Oxygen can be oxidized to ozone.Valency increase from 2 to 3.This is number of possible ion terminals the element can carry.Copper can be reduced to cuprite.cu has -2 as valency charge while cuprite has -3
