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radical, in chemistry

(Encyclopedia)radical, in chemistry, group of atoms that are joined together in some particular spatial structure and that take part in most chemical reactions as a single unit. Important inorganic radicals include...

e, in mathematics

(Encyclopedia)e, in mathematics, irrational number occurring widely in mathematics and science, approximately equal to the value 2.71828; it is the base of natural, or Naperian, logarithms. The number e is defined ...

grain, in agriculture

(Encyclopedia)grain, in agriculture, term referring to the caryopsis, or dry fruit, of a cereal grass. The term is also applied to the seedlike fruits of buckwheat and of certain other plants and is used collective...

glaze, in pottery

(Encyclopedia)glaze, translucent layer that coats pottery to give the surface a finish or afford a ground for decorative painting. Glazes—transparent, white, or colored—are fired on the clay. Of the various art...

canzone, in literature

(Encyclopedia)canzone –nä [key], in literature, Italian term meaning lyric or song. It is used to designate such various literary forms as Provençal troubadour poems and the lyrics of Dante, Petrarch, and other...

ash, in chemistry

(Encyclopedia)ash, in chemistry, solid residue of combustion. The chemical composition of an ash depends on that of the substance burned. Wood ash contains metal carbonates (e.g., potassium carbonate) and oxides fo...

coma, in medicine

(Encyclopedia)coma, in medicine, deep state of unconsciousness from which a person cannot be aroused even by painful stimuli. The patient cannot speak and does not respond to command. Coma is the result of damage t...

Moon Jae-in

(Encyclopedia)Moon Jae-in, 1953–, South Korean political leader, president of South Korea (2017–). The son of North Korean refugees, Moon studied law at Kyung Hee Univ. but was expelled twice for organizing dem...

linden, in botany

(Encyclopedia)CE5 Linden, Tilia americana linden, common name for the Tiliaceae, a family of chiefly woody shrubs and trees. Most genera are tropical, but the genus Tilia, commonly called linden, or lime tree, ...

Playfair, John

(Encyclopedia)Playfair, John, 1748–1819, Scottish mathematician, physicist, and geologist. He was educated at St. Andrews and Edinburgh and taught first mathematics and then physics and astronomy at the latter un...