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element

(Encyclopedia)CE5 element, in chemistry, a substance that cannot be decomposed into simpler substances by chemical means. A substance such as a compound can be decomposed into its constituent elements by means o...

interest

(Encyclopedia)interest, charge for the use of credit or money, usually figured as a percentage of the principal and computed annually. Simple interest is computed annually on the principal. Compound interest, paid ...

hydrogen bomb

(Encyclopedia)hydrogen bomb or H-bomb, weapon deriving a large portion of its energy from the nuclear fusion of hydrogen isotopes. In an atomic bomb, uranium or plutonium is split into lighter elements that togethe...

Angkor

(Encyclopedia)Angkor ăngˈkôr [key], site of several capitals of the Khmer Empire, north of Tônlé Sap, NW Cambodia, for about five and a half centuries (9th to 15th), the heart of the empire. Extending over an ...

calcium

(Encyclopedia)calcium kălˈsēəm [key] [Lat.,=lime], metallic chemical element; symbol Ca; at. no. 20; at. wt. 40.078; m.p. about 839℃; b.p. 1,484℃; sp. gr. 1.55 at 20℃; valence +2. Calcium is a malleable, ...

probability

(Encyclopedia)probability, in mathematics, assignment of a number as a measure of the “chance” that a given event will occur. There are certain important restrictions on such a probability measure. In any exper...

insect

(Encyclopedia)CE5 External anatomy of a female grasshopper, representative of the class Insecta insect, invertebrate animal of the class Insecta of the phylum Arthropoda. Like other arthropods, an insect has a ...

chromatography

(Encyclopedia)chromatography krōˌmətŏgˈrəfē [key], resolution of a chemical mixture into its component compounds by passing it through a system that retards each compound to a varying degree; a system capabl...

energy

(Encyclopedia)CE5 Relations between potential energy (PE) and kinetic energy (KE) for a swinging pendulum energy, in physics, the ability or capacity to do work or to produce change. Forms of energy include hea...

ant

(Encyclopedia)ant, any of the 2,500 insect species constituting the family Formicidae of the order Hymenoptera, to which the bee and the wasp also belong. Like most members of the order, ants have a “wasp waist,�...