oksüüdid

Oksüdid are chemical compounds that consist of one or more oxygen atoms covalently or ionically bonded to another element. They are among the most common and diverse classes of inorganic compounds, found throughout nature and industry. The simplest oxides are binary oxides, formed by reacting oxygen with a single other element, such as metal oxides (CaO, Fe2O3) and nonmetal oxides (CO2, SO3).

Classification: Oxides are typically divided into metal oxides, which are usually basic or amphoteric; nonmetal oxides, which are typically acidic; and amphoteric oxides that show both properties depending on the reactant. Peroxides (containing O-O bonds, e.g., H2O2) and superoxides (like KO2) are related oxide classes. Some oxides, such as alumina (Al2O3) and silica (SiO2), are considered acidic or amphoteric despite being solid and highly stable.

Properties: Oxides vary in structure from ionic lattices in metal oxides to covalent networks in many nonmetal oxides. They have a wide range of melting points and solubilities. Their reactivity with water, acids, and bases often reflects their acid-base character.

Occurrence and production: Oxides form through weathering, combustion, and oxidation processes. Industrially, many metals are obtained by reducing metal oxides; oxides are produced by burning elements in oxygen or oxygen-containing compounds or by oxidation of elements in air.

Uses: Oxides are widely used as construction materials (cement and concrete), pigments, refractories, catalysts, and ceramic materials. Silica and alumina are foundational in glassmaking and ceramics; iron oxides provide pigments; titanium dioxide is a widely used white pigment.

Safety: Some oxides are irritants or toxic in fine powders; others are relatively inert. Handling and emission controls are important to limit air pollution (for example, metal oxide particles and sulfur trioxide).