(chemistry) Any oxide containing two oxygen atoms in each molecule.

plural of dioxide

Archaic form of dioxide.

plural of dioxid

(chemistry) A hard glassy mineral, SiO₂, occurring as quartz, sand, opal etc. Informally known as silica.

(inorganic chemistry) The normal oxide of carbon, CO₂; a colorless, odorless gas formed during respiration and combustion and consumed by plants during photosynthesis.

(inorganic chemistry) A black, semiconducting material, CrO₂, having strong magnetic properties; used in recording tapes.

(chemistry) a brilliant white powder, TiO₂, used as a pigment, and in sunblock, toothpaste and cosmetics

(inorganic chemistry, chiefly British spelling) Alternative spelling of sulfur dioxide

(American spelling, inorganic chemistry) A toxic gas, of molecular formula SO₂ that is found in the emissions of volcanos and those of burning coal or petroleum; dissolves in water to form sulfurous acid and, in the presence of oxygen, sulfuric acid, and is thus responsible for acid rain.