Reduction

Reduction
Points : Reduction, Definition Definition The process of separating the atoms of oxygen from a substance is known a reduction. Reduction is thus the reverse of oxidation, and again, in the wider chemical sense, it refers to a reaction in which the proportion of the electronegative constituent of the molecule is decreased.

Some elements have great affinities for oxygen than have others. Their oxides are therefore more difficult to decompose. Aluminum and Magnesium strongly electropositive metals, have greater affinities for oxygen than has carbon, so that it is impossible to reduce their oxides in the normal way using coke — electrolysis, a much more expensive process, must be used. Metals, such as aluminum, magnesium, zinc, iron and lead, which form stable, tenacious oxides are usually called base metals, whilst those metals which have little affinity for oxygen are called noble metals. Such metals include gold, silver and platinum, metals which will not scale or tarnish to any appreciable extent due to the action of atmospheric oxygen.