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radiochemistry

(Encyclopedia)radiochemistry, chemistry of radioactive substances (see radioactivity). Radioactive isotopes are very useful as tracers to study the mechanisms of complex organic reactions, since even minute amounts...

pineapple

(Encyclopedia)pineapple, common name for one member of and for the Bromeliaceae, a family of chiefly epiphytic herbs and small shrubs native to the American tropics and subtropics. The spiny leaves of various speci...

rotation of crops

(Encyclopedia)rotation of crops, agricultural practice of varying the crops on a piece of land in a planned series, to save or increase the mineral or organic content of the soil, to increase crop yields, and to er...

citric acid

(Encyclopedia)citric acid or 2-hydroxy-1,2,3-propanetricarboxylic acid, HO2CCH2C(OH)(CO2H)CH2CO2H, an organic carboxylic acid containing three carboxyl groups; it is a solid at room temperature, melts at 153℃, an...

List, Benjamin

(Encyclopedia)List, Benjamin, 1968–, b. Frankfurt, Germany. German chemist, Managing Director of the Max Planck Institute for Coal Research and Professor of organic...

Heck, Richard Fred

(Encyclopedia)Heck, Richard Fred, 1931–2015, American chemist, b. Springfield, Mass., Ph.D. Univ. of California, Los Angeles, 1954. Heck was a researcher at the Hercules Corporation in Wilmington, Del., from 1957...

sweetener, artificial

(Encyclopedia)sweetener, artificial, substance used as a low-calorie sugar substitute. Saccharin, cyclamates, and aspartame have been the most commonly used artificial sweeteners. Saccharin, a coal-tar derivative t...

humus

(Encyclopedia)humus hyo͞oˈməs [key], organic matter that has decayed to a relatively stable, amorphous state. It is an important biological constituent of fertile soil. Humus is formed by the decomposing action ...

fatty acid

(Encyclopedia)fatty acid, any of the organic carboxylic acids present in fats and oils as esters of glycerol. Molecular weights of fatty acids vary over a wide range. The carbon skeleton of any fatty acid is unbran...

Olah, George Andrew

(Encyclopedia)Olah, George Andrew, 1927–2017, American chemist, b. Budapest, Ph.D. Budapest Univ. of Technology and Economics, 1949. Olah was a researcher at Dow Chemical from 1957 to 1965 and a professor at West...