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flerovium

(Encyclopedia)flerovium, artificially produced radioactive chemical element; symbol Fl; at. no. 114; mass number of most stable isotope 289; m.p., b.p., sp. gr., and valence unknown. Situated in Group 14 of the per...

electronegativity

(Encyclopedia)electronegativity ĭlĕkˌtrōnĕgətĭvˈətē [key], in chemistry, tendency for an atom to attract a pair of electrons that it shares with another atom (see chemical bond). For example, the molecule...

Aldanov, Mark

(Encyclopedia)Aldanov, Mark əlyĭksänˈdrəvyĭch ləndouˈ [key], 1886–1957, Russian writer. Aldanov earned degrees in chemistry and law. He took part in the Revolution of 1917, after which he emigrated to Fra...

Charpentier, Emmanuelle Marie

(Encyclopedia)Charpentier, Emmanuelle Marie āmänüĕl märēˈ shärpäNtyāˈ [key], 1968–, French microbiologist, Ph.D. Pierre and Marie Curie Univ., 1995. Following postdoctoral appointments at several insti...

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...

Lockyer, Sir Joseph Norman

(Encyclopedia)Lockyer, Sir Joseph Norman lŏkˈyər [key], 1836–1920, English astronomer, educated on the Continent. One of the first to make a spectroscopic examination of the sun and stars, he devised (1868), i...

Sverdrup, Harald Ulrik

(Encyclopedia)Sverdrup, Harald Ulrik häˈräl o͞olˈrĭk svĕrˈdro͝op [key], 1888–1957, Norwegian oceanographer and meteorologist. He was in charge of the scientific work on the Maud for Amundsen's arctic exp...

Sharpless, Karl Barry

(Encyclopedia)Sharpless, Karl Barry, 1941–, American chemist, b. Philadelphia, Ph.D. Stanford, 1968. Sharpless was a professor at the Massachusetts Institute of Technology (1970–77 and 1980–90) and at Stanfor...

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...

alkyl group

(Encyclopedia)alkyl group ălˈkĭl [key], in chemistry, group of carbon and hydrogen atoms derived from an alkane molecule by removing one hydrogen atom (see radical). The name of the alkyl group is derived from t...