oxygenanion
An oxygen anion is a negatively charged ion of oxygen. Oxygen, a highly electronegative element, readily gains electrons to achieve a stable electron configuration. When oxygen gains one or more electrons, it forms an anion. The most common oxygen anion is the oxide ion, O^2-, where oxygen has gained two electrons. This species is found in many ionic compounds, such as metal oxides like magnesium oxide (MgO) and iron(III) oxide (Fe2O3). Other oxygen anions exist, such as the superoxide ion, O2^-, which has a net charge of -1 and contains a single oxygen-oxygen bond. The peroxide ion, O2^2-, also has a net charge of -2 and features a single oxygen-oxygen bond. These polyatomic oxygen anions are important in various chemical and biological processes. For example, superoxide radicals play a role in cellular respiration and immune responses, while peroxides are utilized as oxidizing agents and in bleaching applications. The charge and structure of oxygen anions are determined by the number of electrons gained and how the oxygen atoms are bonded together.