氧化还原反应是化学中最重要的化学反应之一。在化学发展史中,曾经把物质与氧结合或者失去氢的过程叫做氧化;而把物质与氢结合或者失去氧的过程称为还原。后来,随着生产实践和科学技术的发展,人们的认识不断深化,不再满足于表面现象而寻求事物的本质。19世纪中叶在化学中采用了原子价的概念,因此,人们从原子价变化着眼,提出了氧化——还原的新定义。如反应中物质分子里,某元素正价升高,或负价降低,就说该元素被氧化;反之则是被还原。从反应中电子得失的角度出发, Redox reactions are one of the most important chemical reactions in chemistry. In the history of chemical development, the process of combining matter with oxygen or losing hydrogen is called oxidation; the process of combining a substance with hydrogen or losing oxygen is called reduction. Later, with the development of production practices and science and technology, people’s understanding has deepened, and they are no longer content with the surface phenomena and seek the essence of things. In the mid-19th century, the concept of atomic valence was adopted in chemistry. Therefore, from the perspective of changes in the atomic price, people proposed a new definition of oxidation-reduction. For example, if the price of an element increases or the negative price decreases in a substance molecule in the reaction, the element is said to be oxidized; otherwise, it is reduced. From the perspective of electronic gains and losses in the reaction,