An oxidizing agent (also called an oxidant, oxidizer or oxidiser) can be defined as either: a chemical compound that readily transfers oxygen atoms, or a substance that gains electrons in a redox chemical reaction. In both cases, the oxidizing agent becomes reduced in the process.The oxidizing agent is reduced. The reducing agent is oxidized. All atoms in a molecule can be assigned an oxidation number. This number changes when an oxidant acts on a substrate. Redox reactions occur when oxidation states of the reactants change.

Common oxidizing agents

peroxide and other inorganic Peroxides
and s
Chlorite, chlorate, perchlorate, and other analogous halogen compounds
Hypochlorite and other hypohalite compounds such as bleach
and other halogens

(N₂O)
oxide
salts
Hexavalent chromium compounds such as chromic and dichromic acids and chromium trioxide, pyridinium chlorochromate (PCC), and chromate/dichromate compounds
Peric acid
Sulfoxides

Tollens' reagent
disulfide aka DPS
tetroxide (OsO₄)

Common oxidizing agents and their products