What type of reaction occurs when atoms of the reactants change their oxidation states?

The type of reaction where atoms of the reactants change their oxidation states is known as an oxidation-reduction reaction, often referred to as a redox reaction. In these reactions, one species undergoes oxidation by losing electrons and increasing its oxidation state, while another species undergoes reduction by gaining electrons and decreasing its oxidation state. This transfer of electrons is a fundamental characteristic of redox reactions and is crucial for various biological, chemical, and industrial processes.

In contrast, precipitation reactions involve the formation of a solid from a solution, but there is no change in oxidation states involved in that process. Acid-base reactions focus on the transfer of protons (H+) and do not change the oxidation states of the reactants. Synthesis reactions involve the combination of two or more substances to form a new compound but do not necessarily involve oxidation state changes in the participating reactants. Therefore, the fundamental concept that defines oxidation-reduction reactions directly links to the alteration of oxidation states among the reactants during the reaction process.