👉 In chemistry, an oxidation state is a symbol used to represent how many electrons are available for a substance to lose from its chemical structure. The term "oxidising" refers to a process by which an element loses electrons in order to form an oxide (a compound that contains at least one metal atom). Oxidizing processes can range from simple reactions involving the loss of hydrogen atoms (e.g., combustion) to more complex transformations, such as those found in the decomposition of organic compounds.