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Liebig, Justus, Baron von

(Encyclopedia)Liebig, Justus, Baron von yo͝osˈto͝os bärônˈ fən lēˈbĭkh [key], 1803–73, German chemist. As professor at Giessen (1824–52), he was among the first to establish a chemical teaching labora...

lapis lazuli

(Encyclopedia)lapis lazuli lăpˈĭs lăzˈo͝olē [key], gem, deep blue, violet, or greenish blue in color and usually flecked with yellow iron pyrites. It is composed of lazurite, a complex sodium aluminum silica...

spotted lanternfly

(Encyclopedia)spotted lanternfly, common name for a planthopper, Lycorma delicatula, an insect that is native to China, India, and Vietnam, and is an introduced agricultural pest in Korea and the United States. The...

ring, piece of jewelry

(Encyclopedia)ring, small ornamental hoop usually worn on finger or thumb, but it may be attached to the ear or the nose. Finger rings made of bronze, gold, and silver from the period c.2600–1500 b.c. have been f...

bauxite

(Encyclopedia)bauxite bôkˈsīt, bŏkˈ– [key], mixture of hydrated aluminum oxides usually containing oxides of iron and silicon in varying quantities. A noncrystalline substance formerly thought to be a minera...

ytterbium

(Encyclopedia)ytterbium ĭtûrˈbēəm [key] [for Ytterby, a town in Sweden], metallic chemical element; symbol Yb; at. no. 70; at. wt. 173.054; m.p. 819℃; b.p. about 1,194℃; sp. gr. about 7.0; valence +2 or +3...

ammonium group

(Encyclopedia)ammonium group, in chemistry, a positively charged nitrogen atom joined by single bonds to four other atoms or groups. The simplest ammonium group, NH4+, is formed by protonation of ammonia, NH3, e.g....

connective tissue

(Encyclopedia)connective tissue, supportive tissue widely distributed in the body, characterized by large amounts of intercellular substance and relatively few cells. The intercellular material, or matrix, is produ...