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acid anhydride

(Encyclopedia)acid anhydride ănhīˈdrīd, –drəd [key], chemical compound that reacts with water to form an acid (see acids and bases). Anhydrides of inorganic acids are usually oxides of nonmetallic elements. ...

Sudbury, city, Canada

(Encyclopedia)Sudbury, city (1991 pop. 92,884), central Ont., Canada. It is the center of Canada's largest mining region, which produces much of the world's nickel and large quantities of copper, platinum, gold, si...

Caltagirone

(Encyclopedia)Caltagirone kälˌtäjērôˈnā [key], city, SE Sicily, Italy. An agricultural and sulfur-mining center, ...

oxide

(Encyclopedia)oxide, chemical compound containing oxygen and one other chemical element. Oxides are widely and abundantly distributed in nature. Water is the oxide of hydrogen. Silicon dioxide is the major componen...

selenium

(Encyclopedia)selenium səlēˈnēəm [key], nonmetallic chemical element; symbol Se; at. no. 34; at. wt. 78.96; m.p. 217℃; b.p. about 685℃; sp. gr. 4.81 at 20℃; valence −2, +4, or +6. Selenium is directly ...

Mieres

(Encyclopedia)Mieres mēāˈrĕs [key], city (1990 pop. 57,627), Oviedo prov., N Spain, in Asturias, on the Lena River. It is an important mining center for coal, sulfur, and cinnabar and has iron and steel plants....

Turner Valley

(Encyclopedia)Turner Valley, village (1991 pop. 1,352), SW Alta., Canada, at the foot of the Rocky Mts., on the Sheep River, SW of Calgary. It is in the center of the Turner Valley oil and natural gas fields, opene...

dandruff

(Encyclopedia)dandruff, excessive flaking of skin from the scalp, apparent as dry or greasy diffuse scaling with variable itching. It is the sign of a skin disease, such as seborrhea or a fungal infection. Treatmen...

Bagnères-de-Luchon

(Encyclopedia)Bagnères-de-Luchon bänyĕrˌ-də-lüshôNˈ [key], town, Haute-Garonne dept., S France, at the foot of the Maladetta Mts. It is an important resort in the Pyrenees. Its warm sulfur springs have been...

germanium

(Encyclopedia)germanium jərmāˈnēəm [key] [from Germany], semimetallic chemical element; symbol Ge; at. no. 32; at. wt. 72.63; m.p. 937.4℃; b.p. 2,830℃; sp. gr. 5.323 at 25℃; valence +2 or +4. Pure german...