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chemosynthesis

(Encyclopedia)chemosynthesis, process in which carbohydrates are manufactured from carbon dioxide and water using chemical nutrients as the energy source, rather than the sunlight used for energy in photosynthesis....

nucleosynthesis

(Encyclopedia)nucleosynthesis or nucleogenesis, in astronomy, production of all the chemical elements from the simplest element, hydrogen, by thermonuclear reactions within stars, supernovas, and in the big bang at...

Pluto, in astronomy

(Encyclopedia)Pluto, in astronomy, a dwarf planet and the first Kuiper belt, or transneptunian, object (see comet) to be discovered (1930) by astronomers. Pluto has an elliptical orbit usually lying beyond that of ...

Leuna

(Encyclopedia)Leuna loiˈnä [key], city (1994 pop. 8,130), Saxony-Anhalt, S central Germany. There, in 1916, the first synthetic nitrogen plant began to operate after the invention of the Haber process. The city w...

rhodium

(Encyclopedia)rhodium rōˈdēəm [key], metallic chemical element; symbol Rh; at. no. 45; at. wt. 102.90550; m.p. about 1,966℃; b.p. 3,727±100℃; sp. gr. 12.41 at 20℃; valence +2, +3, +4, +5, or +6. Rhodium ...

vetch

(Encyclopedia)vetch, common name for many weak-stemmed, leguminous herbs of the genus Vicia of the family Leguminosae (pulse family). The vetches are chiefly annuals, distributed over temperate regions of the North...

cryosurgery

(Encyclopedia)cryosurgery krīˈōsrˌjərē [key], bloodless surgical technique using a supercooled probe to destroy diseased or superfluous tissue. Liquid nitrogen circulating through the instrument cools it to t...

nonmetal

(Encyclopedia)nonmetal, chemical element possessing certain properties by which it is distinguished from a metal. In general, this distinction is drawn on the basis that a nonmetal tends to accept electrons and for...

symbiosis

(Encyclopedia)symbiosis sĭmbēōˈsĭs [key], the habitual living together of organisms of different species. The term is usually restricted to a dependent relationship that is beneficial to both participants (als...

compost

(Encyclopedia)compost, substance composed mainly of partly decayed organic material that is applied to fertilize the soil and to increase its humus content; it is often used in vegetable farming, home gardens, flow...