oxide(redirected from trioxide)
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a chemical compound in which an element is combined with oxygen. Some oxides form salts, for example, Na2O, MgO, Al2O3, SiO2, P2O5, SO3 and C12O7; others, including CO, N2O, NO, and H2O, do not. Oxides that form salts are basic, acid, or amphoteric; accordingly, their hydroxides are bases, acids, or amphoteric compounds. The chemical activity of oxides is determined by the location of the oxidized elements in D. I. Mendeleev’s periodic table of the elements.
Many oxides occur naturally, such as water (H2O), carbon dioxide (CO2), and silica (SiO2, a primary constituent of rocks). The natural oxides of certain elements, including iron and tin, are the starting material for the preparation of the corresponding pure metal. Oxides are widely used in engineering, for example, lime (CaO) is used in construction. Nitric and sulfuric acids are prepared from NO2 and SO2.
a chemical compound in which oxygen is combined only with more electropositive elements. Examples of oxides are chromous oxide (CrO) and chromic oxide:
The term “oxide” has been incorporated into the international nomenclature for inorganic compounds; the equivalent for this term in the Russian nomenclature is okisel.