Oxidation

Oxidants

Oxidation originally implied a reaction with oxygen to form an oxide. Later, the term expanded to encompass chemical reactions similar to those with oxygen. Ultimately, the meaning became generalized to include all processes that involve the loss of electrons or the increase in the oxidation state of a chemical species. Substances that have the ability to oxidize other substances (cause them to lose electrons) are said to be oxidative or oxidizing, and are known as oxidizing agents, oxidants, or oxidizers. The oxidant removes electrons from another substance, and is thus itself reduced. Because it "accepts" electrons, the oxidizing agent is also called an electron acceptor. Oxidants are usually chemical substances with elements in high oxidation states (e.g., N
₂O
₄, MnO
₄, CrO
₃, Cr
₂O
₇, OsO
₄), or else highly electronegative elements (e.g. O₂, F₂, Cl₂, Br₂, I₂) that can gain extra electrons by oxidizing another substance.