What does oxidation mean?
Oxidation is the process by which a substance undergoes an increase in its oxidation state, most commonly by losing electrons; in everyday chemistry teaching, it is often described as a substance combining with oxygen. Metals may oxidize to form oxides, and iron can develop rust as a result of oxidation in the presence of moisture. The term also has a broader figurative use for gradual deterioration or transformation, as in the oxidation of old photographs or the oxidation of political ideals. In formal chemical contexts, oxidation is precisely paired with reduction: electrons are lost in one process and gained in the other. The word is especially useful in discussions of chemistry, metallurgy, corrosion, batteries, and environmental degradation.
nounThe chemical process in which a substance combines with oxygen or undergoes an increase in its oxidation state, typically involving the loss of electrons. In figurative use, it refers to deterioration, corrosion, or the gradual transformation of a material or condition.
- The chemical process of combining a substance with oxygen or increasing its oxidation state, especially through the loss of electrons.
- The gradual deterioration or transformation of a material, such as the oxidation of iron into rust.
"The oxidation of iron in the presence of moisture eventually produces rust."
"Heat accelerated the oxidation of the metal surface."
"The coating slows oxidation and helps preserve the underlying steel."
Usually used in technical or scientific contexts when referring to separate instances or types of oxidation.
"The researchers compared the oxidations of several metals under controlled conditions."
Oxidation is the chemical partner of reduction: together they form one of the most important exchanges in chemistry, helping explain batteries, rusting, burning, and corrosion.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does oxidation come from?
Oxidation comes from the Latin root oxid-, meaning “egg” or “sour,” an ancient association with the sharp-tasting effect of substances formed by oxidation. The term was developed in the language of chemistry from French and Latin formations based on oxygen, whose name combines the Greek roots for “acid” and “producer.” Cognate and related words include oxygen, oxide, and oxidizer.
Related word forms
How oxidation is actually used
In chemistry, oxidation has a precise meaning and is not restricted to reactions involving molecular oxygen. In general use, it often describes tarnishing, corrosion, or deterioration caused by exposure to air or other oxidizing agents.
Easily confused with oxidation
Oxidation involves an increase in oxidation state and, commonly, a loss of electrons, whereas reduction involves a decrease in oxidation state and a gain of electrons.