Monoxid

Monoxid is a term used in chemistry to refer to a binary compound composed of oxygen and another element where the molecule or formula unit contains one oxygen atom. In English, the standard term is monoxide. The concept encompasses a diverse set of species, including gaseous molecules such as carbon monoxide (CO), nitrogen monoxide (NO), and sulfur monoxide (SO), as well as solid metal monoxides like iron(II) oxide (FeO) and manganese(II) oxide (MnO).

Monoxides can be formed by metals, nonmetals, and metalloids, and their properties vary widely. Gaseous monoxides may be toxic or reactive; for example, carbon monoxide is a colorless, odorless, toxic gas, while nitrogen monoxide participates in atmospheric chemistry and biological signaling at low concentrations. Solid metal monoxides often arise from partial oxidation and can display different crystal structures and oxidation states. Some monoxides are unstable and exist only transiently under certain conditions, whereas others are stable crystalline solids used in industrial processes or materials science.

Nomenclature generally follows the pattern “X oxide” or “X monoxide,” where X is the element. The prefix mono- signals a single oxygen atom in the formula unit, though actual stoichiometry and oxidation states can vary among different compounds. Monoxides are distinguished from higher oxides (such as peroxides and superoxides) by the number and arrangement of oxygen atoms and by their typical bonding character.

Safety and handling depend on the specific compound. Many monoxides are reactive or toxic, and proper laboratory practices, ventilation, and containment are essential when working with them.