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insecticides

(Encyclopedia)insecticides, chemical, biological, or other agents used to destroy insect pests; the term commonly refers to chemical agents only. The liabilities of chemical insecticides have encouraged interest ...

photosynthesis

(Encyclopedia)photosynthesis fōˌtōsĭnˈthəsĭs [key], process in which green plants, algae, and cyanobacteria utilize the energy of sunlight to manufacture carbohydrates from carbon dioxide and water in the pr...

caustic

(Encyclopedia)caustic, any strongly corrosive chemical substance, especially one that attacks organic matter. A caustic alkali is a metal hydroxide, especially that of an alkali metal; caustic soda is sodium hydrox...

Hassel, Odd

(Encyclopedia)Hassel, Odd ôd häsˈəl [key], 1897–1981, Norwegian chemist, b. Christiania (now Oslo), grad. Oslo Univ. (1920), Ph.D. Univ. of Berlin (1924). After pursuing X-ray crystallographic studies in Germ...

anthracene

(Encyclopedia)CE5 anthracene ănˈthrəsēn [key], C14H10, solid organic compound derived from coal tar. It melts at 218℃ and boils at 354℃. When pure it is colorless and has a violet fluorescence; it darken...

ketone

(Encyclopedia)CE5 Ketones ketone kēˈtōn [key], any of a class of organic compounds that contain the carbonyl group, C=O, and in which the carbonyl group is bonded only to carbon atoms. The general formula fo...

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...

oxalic acid

(Encyclopedia)oxalic acid ĕthˌāndīōĭk [key], HO2CCO2H, a colorless, crystalline organic carboxylic acid that melts at 189℃ with sublimation. Oxalic acid and oxalate salts are poisonous. Oxalic acid is found...

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...

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...