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Slovakia

(Encyclopedia)CE5 Slovakia slôˈvĕnskô [key], republic (2015 est. pop. 5,439,000), 18,917 sq mi (48,995 sq km), central Europe. It is bordered by the Czech Republic in the west, by Austria in the southwest, b...

Uzbekistan

(Encyclopedia)CE5 Uzbekistan o͝ozbĕkĭstänˈ [key], Uzbek Ozbekiston, officially Republic of Uzbekistan, republic (2015 est. pop. 29,200,000), 173,552 sq mi (449,500 sq km), central Asia. The republic, which ...

drugs

(Encyclopedia)drugs, substances used in medicine either externally or internally for curing, alleviating, or preventing a disease or deficiency. At the turn of the century only a few medically effective substances ...

laser

(Encyclopedia)CE5 Ordinary light sources produce incoherent light, while a laser produces a beam of coherent light. laser [acronym for light amplification by stimulated emission of radiation], device for the cr...

water

(Encyclopedia)CE5 A. Water molecule (black circles represent valence-shell electrons) B. Structure of ice: Each oxygen atom (white circles) is bonded to four other oxygen atoms by hydrogen bonds, the hydrogen at...

carbon

(Encyclopedia)CE5 The three solid forms of pure carbon: In the diamond crystal each carbon atom is surrounded symmetrically by four other carbons (at each of the four corners of a tetrahedron). In the graphite c...

acids and bases

(Encyclopedia)acids and bases, two related classes of chemicals; the members of each class have a number of common properties when dissolved in a solvent, usually water. Another theory that provides a very broad ...

fire fighting

(Encyclopedia)fire fighting, the use of strategy, personnel, and apparatus to extinguish, to confine, or to escape from fire. Ancient Rome is known to have had a fire department consisting by the 1st cent. of app...

iron

(Encyclopedia)iron, metallic chemical element; symbol Fe [Lat. ferrum]; at. no. 26; at. wt. 55.845; m.p. about 1,535℃; b.p. about 2,750℃; sp. gr. 7.87 at 20℃; valence +2, +3, +4, or +6. Iron is biologically s...

Industrial Revolution

(Encyclopedia)Industrial Revolution, term usually applied to the social and economic changes that mark the transition from a stable agricultural and commercial society to a modern industrial society relying on comp...