Oxidation-reduction reactions of iron

Oxidation-reduction reactions are opposites. When electrons are added to an atom, chemists say it is being reduced, and it becomes negatively charged. When electrons are removed from an atom, then it is being oxidized, and it becomes more positively charged. An atom can gain, then lose, then gain, then lose electrons an unlimited number of times, depending on chemistry and environmental conditions.

Oxidation-reduction reactions cause the colorful “life” of iron atoms. Sometimes they will be reduced and dissolve into fluids. In this form they can move more freely. At other times they will be oxidized and immovably fixed in place. In this form they’ll be visible as a colored pigment.