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Liancourt Rocks

(Encyclopedia)Liancourt Rocks, Jap. Takeshima, Korean Dokdo or Tokdo, island group, 58 acres (23 hectares), in the SW Sea of Japan, roughly midway between the Japanese island of Honshu and the Korean peninsula. Con...

scheelite

(Encyclopedia)scheelite shāˈlīt, shēˈ– [key], heavy white or yellow mineral, calcium tungstate, CaWO4, crystallizing in the tetragonal system. It is found in granite pegmatites, in contact-metamorphic deposi...

pyrolusite

(Encyclopedia)pyrolusite pīˈrōlo͞ozīt [key], naturally occurring manganese dioxide, MnO2, a black mineral that crystallizes in the tetragonal system but is usually found in earthy or massive deposits. It is th...

pyrrhotite

(Encyclopedia)pyrrhotite pĭrˈətīt [key] or magnetic pyrites, bronze-yellow to bronze-red mineral, a sulfide of iron sometimes containing nickel. It tarnishes easily and is somewhat magnetic. It crystallizes in ...

Ouachita Mountains

(Encyclopedia)Ouachita Mountains, range of east-west ridges between the Arkansas and Red rivers, extending c.200 mi (320 km) from central Ark. into SE Okla. Magazine Mt. (c.2,800 ft/850 m high) is the tallest peak....

laetrile

(Encyclopedia)laetrile lāˈətrĭlˌ [key], name given to the chemical amygdalin, a substance derived from an extract of the kernels of many fruits, notably apricots, bitter almonds, and peaches. The idea that lae...

amide

(Encyclopedia)amide ămˈīd [key], organic compound formed by reaction of an acid chloride, acid anhydride, or ester with an amine. Under strong acidic conditions an amide can be hydrolyzed to yield an amine and a...

indicators, acid-base

(Encyclopedia)indicators, acid-base, organic compounds that, in aqueous solution, exhibit color changes indicative of the acidity or basicity of the solution. Common indicators include p-nitrophenol, which is color...

Hoffmann, Josef

(Encyclopedia)Hoffmann, Josef, 1870–1956, Austrian architect. A student of Otto Wagner, he was a leader of Austrian decoration in the first three decades of the 20th cent. His sophisticated compositions, based on...

chloride

(Encyclopedia)chloride klōrˈīd, klôrˈ– [key], chemical compound containing chlorine. Most chlorides are salts that are formed either by direct union of chlorine with a metal or by reaction of hydrochloric ac...