Columbia Encyclopedia

Search results

438 results found

chromium

(Encyclopedia)chromium krōˈmēəm [key] [Gr.,=color], metallic chemical element; symbol Cr; at. no. 24; at. wt. 51.9961; m.p. about 1,857℃; b.p. 2,672℃; sp. gr. about 7.2 at 20℃; valence +2, +3, +6. Chromiu...

lanthanide series

(Encyclopedia)lanthanide series, a series of metallic elements, included in the rare-earth metals, in Group 3 of the periodic table. Members of the series are often called lanthanides, although lanthanum (atomic nu...

titanium

(Encyclopedia)titanium tītāˈnēəm, tĭ– [key] [from Titan], metallic chemical element; symbol Ti; at. no. 22; at. wt. 47.867; m.p. 1,675℃; b.p. 3,260℃; sp. gr. 4.54 at 20℃; valence +2, +3, or +4. Titani...

blood groups

(Encyclopedia)blood groups, differentiation of blood by type, classified according to immunological (antigenic) properties, which are determined by specific substances on the surface of red blood cells. Blood group...

bohrium

(Encyclopedia)bohrium bôrˈēəm [key], artificially produced radioactive chemical element; symbol Bh; at. no. 107; mass number of most stable isotope 270; m.p., b.p., sp. gr., and valence unknown. Situated in Gro...

quasicrystal

(Encyclopedia)quasicrystal kwāˈzīkrĭsˌtəl, kwäzˈē– [key] or quasiperiodic solid, solid body that exhibits such crystalline features as symmetry and repeating patterns of unit cells (regular arrangements ...

Seaborg, Glenn Theodore

(Encyclopedia)Seaborg, Glenn Theodore sēˈbôrg [key], 1912–99, American chemist, b. Ishpeming, Mich., grad. Univ. of California at Los Angeles, 1934, Ph.D. Univ. of California at Berkeley, 1937. In 1939, he beg...

periodic table

(Encyclopedia)CE5 periodic table, chart of the elements arranged according to the periodic law discovered by Dmitri I. Mendeleev and revised by Henry G. J. Moseley. In the periodic table the elements are arrange...

alcohol

(Encyclopedia)CE5 Alcohols alcohol, any of a class of organic compounds with the general formula R–OH, where R represents an alkyl group made up of carbon and hydrogen in various proportions and –OH represe...

corticosteroid drug

(Encyclopedia)corticosteroid drug kôrˌtəkōstârˈoid [key], any one of several synthetic or naturally occurring substances with the general chemical structure of steroids. They are used therapeutically to mimic...