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aureole, in physics

(Encyclopedia)aureole ôrˈēōlˌ [key], in physics, luminous circle seen when the sun or other bright light is observed through a diffuse medium, i.e., smoke, thin cloud, fog, haze, or mist. It sometimes occurs a...

mole, in chemistry

(Encyclopedia)mole, in chemistry, a quantity of particles of any type equal to Avogadro's number, or 6.02×1023 particles. One gram-molecular weight of any molecular substance contains exactly one mole of molecules...

bow, in music

(Encyclopedia)bow bō [key], implement used in playing stringed instruments. Its name originated from the fact that in its early form it resembled an archer's bow, but by the 17th cent. the European bow had gradual...

nut, in botany

(Encyclopedia)nut, in botany, a dry one-seeded fruit which is indehiscent (i.e., does not split open along a definite seam at maturity). Among the true nuts are the acorn, chestnut, and hazelnut. Commonly the word ...

bellflower, in botany

(Encyclopedia)bellflower or bluebell, name commonly used as a comprehensive term for members of the Campanulaceae, a family of chiefly herbaceous annuals or perennials of wide distribution, characteristically found...

rhea, in zoology

(Encyclopedia)rhea rēˈə [key], common name for a South American bird of the family Rheidae, which is related to the ostrich. Weighing from 44 to 55 lb (20–25 kg) and standing up to 60 in. (152 cm) tall, the rh...

locust, in zoology

(Encyclopedia)locust, in zoology, name for certain migratory members of the short-horned grasshopper family (Acrididae). Like other members of this family, locusts have antennae shorter than their bodies, song-prod...

nucleus, in physics

(Encyclopedia)nucleus, in physics, the extremely dense central core of an atom. Following the discovery of radioactivity by A. H. Becquerel in 1896, Ernest Rutherford identified two types of radiation given off b...

bark, in botany

(Encyclopedia)bark, outer covering of the stem of woody plants, composed of waterproof cork cells protecting a layer of food-conducting tissue—the phloem or inner bark (also called bast). As the woody stem increa...

magnolia, in botany

(Encyclopedia)magnolia, common name for plants of the genus Magnolia, and for the Magnoliaceae, a family of deciduous or evergreen trees and shrubs, often with showy flowers. They are principally of north temperate...