(chemistry) The chemical compound FeO, iron oxide where iron has a valence of +2.

(chemistry) The chemical compound Fe₂O₃, iron oxide where iron has a valence of +3.

(inorganic chemistry) The solid, Al₂O₃, commonly known as alumina; it occurs as bauxite, sapphire, ruby and other forms; it is used in the manufacture of ceramics

(chemistry) An amorphous solid, ZnO, white when pure but often pale yellow, used in pigments and cosmetics

(inorganic chemistry) A white powderous substance, CaO, normally made by heating calcium carbonate.

(inorganic chemistry) A white powder (MgO) with a high melting point; it occurs naturally as periclase, an ore of magnesium.

(organic chemistry) diethyl ether.

(chemistry) A thermoplastic polyether resin whose repeat unit is derived from hydroquinone

(inorganic chemistry) A white solid, of empirical formula B₂O₃; it is an inorganic polymer used in making glass and enamel and for synthesizing other boron compounds.

(inorganic chemistry) A yellow oxide of lead, PbO, used in the manufacture of paints and glass.