A reaction in which the same element is simultaneously oxidized and reduced is called a:

1. Ordinarily, oxidation happens to one substance and reduction happens to another in a redox reaction. 2. The text names the special case where this happens to the same element: "Reactions in which the same element is both oxidized and reduced are called disproportionation reactions." 3. "Combination," "passivation," and "amalgamation" reactions describe entirely different chemical processes (synthesis, oxide-coating formation, and mercury-alloying, respectively). 4. So the correct term for an element being both oxidized and reduced in the same reaction is disproportionation. _Source: OpenStax Chemistry Ch 18 "Representative Metals, Metalloids, and Nonmetals", p.988 §18.4 Structure and General Properties of the Nonmetals_