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fluxional molecules
(Encyclopedia)fluxional molecules, molecules that exhibit rapid intramolecular rearrangements among their component atoms. As in structural isomerism and tautomerism (see isomer; tautomer), fluxional compounds main...mass transit
(Encyclopedia)mass transit, public transportation systems designed to move large numbers of passengers. The history of mass transportation is intimately connected to industrialization, urbanization, and the sepa...Haber process
(Encyclopedia)Haber process häˈbər [key], commercial process for the synthesis of ammonia, NH3. Pure hydrogen and nitrogen gases are mixed in the appropriate proportion, heated to between 450℃ and 600℃, comp...thirst
(Encyclopedia)thirst, sensation indicating the body's need for water. Dry or salty food and dry, dusty air may induce such a sensation by depleting moisture in the mucous membranes of the mouth and throat. Relief t...thunder
(Encyclopedia)thunder, sound produced along a path of a lightning flash, caused by the rapid heating and expansion of the adjacent air; lightning can heat air to temperatures as much as five times hotter than those...Bican, Josef
(Encyclopedia)Bican, Josef, 1913–2001, Czech soccer player, b. Vienna. A forward with over 800 competitive goals, he is considered by many to be soccer's greatest scorer. Known as “Pepi,” Bican joined Rapid V...Biobío
(Encyclopedia)Biobío bēˈō– [key], river, c.240 mi (390 km) long, rising in the Andes of central Chile and flowing NW to the Pacific Ocean near Concepción. It forms a natural divide between middle and souther...World Meteorological Organization
(Encyclopedia)World Meteorological Organization (WMO), specialized agency of the United Nations; established in 1950 with headquarters at Geneva, it became affiliated with the United Nations a year later. It replac...pothole
(Encyclopedia)pothole, in geology, cylindrical pit formed in the rocky channel of a turbulent stream. It is formed and enlarged by the abrading action of pebbles and cobbles that are carried by eddies, or circular ...Philadelphia, city, United States
(Encyclopedia)Philadelphia, city (2020 pop. 1,603,797), coextensive with Philadelphia co., SE Pa., on the Delaware River c.100 mi (160 km) upstream at the influx of t...Browse by Subject
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