Columbia Encyclopedia

Search results

500 results found

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...

Janus, in astronomy

(Encyclopedia)Janus jāˈnəs [key], in astronomy, one of the named moons, or natural satellites, of Saturn. Also known as Saturn X (or S10), Janus is an irregularly shaped (nonspherical) body measuring about 122 m...

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...

Juno, in astronomy

(Encyclopedia)Juno jo͞oˈnō [key], in astronomy, 3d asteroid to be discovered. It was found in 1804 by C. Harding. It has a diameter of c.120 mi (190 km). Its average distance from the sun is 2.67 astronomical un...

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...

Calypso, in astronomy

(Encyclopedia)Calypso, in astronomy, one of the named moons, or natural satellites, of Saturn. Also known as Saturn XIV (or S14), Calypso is a small, irregularly shaped (nonspherical) body measuring about 21 mi (34...

sun, in astronomy

(Encyclopedia)CE5 Structure of the sun sun, intensely hot, self-luminous body of gases at the center of the solar system. Its gravitational attraction maintains the planets, comets, and other bodies of the sola...

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...