Oxidizing agent The substance that oxidizes

Oxidizing agent The substance that oxidizes another substance... 

Oxidizing agent The substance that appears to cause an oxidation to occur, by accepting or appearing to accept electrons. 

Reducing agent The substance that reduces another substance and is oxidized. 

Oxidation-reduction reactions are sometimes divided into half-reactions to separate and clarify the electron transfer process. The species that loses electrons is said to be oxidized, and the species that gains electrons is said to be reduced. The oxidized species is often referred to as the reducing agent. The substance that is reduced is referred to as the oxidizing agent. 

Depending on the context, oxidation can either refer to (a) a reaction in which oxygen combines chemically with another substance or (b) any reaction in which electrons are transferred. For the latter definition, oxidation and reduction always occur simultaneously (redox reactions), and the substance that gains electrons is termed the oxidizing agent. Electrons might also be displaced within a molecule without being completely transferred away from it. 

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