a small part of a solid substance (

См. также в других словарях:

• Pore — may refer to:In animal biology and microbiology: * Sweat pore, an anatomical structure of the skin of humans (and other mammals) used for secretion of sweat * Canal pore, an anatomical structure that is part of the lateral line sense system of… …   Wikipedia

• separation and purification — ▪ chemistry Introduction       in chemistry, separation of a substance into its components and the removal of impurities. There are a large number of important applications in fields such as medicine and manufacturing. General principles… …   Universalium

• radiation — radiational, adj. /ray dee ay sheuhn/, n. 1. Physics. a. the process in which energy is emitted as particles or waves. b. the complete process in which energy is emitted by one body, transmitted through an intervening medium or space, and… …   Universalium

• Earth Sciences — ▪ 2009 Introduction Geology and Geochemistry       The theme of the 33rd International Geological Congress, which was held in Norway in August 2008, was “Earth System Science: Foundation for Sustainable Development.” It was attended by nearly… …   Universalium

• electromagnetic radiation — Physics. radiation consisting of electromagnetic waves, including radio waves, infrared, visible light, ultraviolet, x rays, and gamma rays. [1950 55] * * * Energy propagated through free space or through a material medium in the form of… …   Universalium

• United States — a republic in the N Western Hemisphere comprising 48 conterminous states, the District of Columbia, and Alaska in North America, and Hawaii in the N Pacific. 267,954,767; conterminous United States, 3,022,387 sq. mi. (7,827,982 sq. km); with… …   Universalium

• Europe, history of — Introduction       history of European peoples and cultures from prehistoric times to the present. Europe is a more ambiguous term than most geographic expressions. Its etymology is doubtful, as is the physical extent of the area it designates.… …   Universalium

• atom — /at euhm/, n. 1. Physics. a. the smallest component of an element having the chemical properties of the element, consisting of a nucleus containing combinations of neutrons and protons and one or more electrons bound to the nucleus by electrical… …   Universalium

• Chemical element — The periodic table of the chemical elements A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus.[1] Familiar examples of …   Wikipedia

• fluid mechanics — an applied science dealing with the basic principles of gaseous and liquid matter. Cf. fluid dynamics. [1940 45] * * * Study of the effects of forces and energy on liquids and gases. One branch of the field, hydrostatics, deals with fluids at… …   Universalium

• gas — gasless, adj. /gas/, n., pl. gases, v., gassed, gassing. n. 1. Physics. a substance possessing perfect molecular mobility and the property of indefinite expansion, as opposed to a solid or liquid. 2. any such fluid or mixture of fluids. 3. any… …   Universalium