Columbia Encyclopedia

Search results

500 results found

oxidation and reduction

(Encyclopedia)oxidation and reduction, complementary chemical reactions characterized by the loss or gain, respectively, of one or more electrons by an atom or molecule. Originally the term oxidation was used to re...

zirconium

(Encyclopedia)zirconium zərkōˈnēəm [key], metallic chemical element; symbol Zr; at. no. 40; at. wt. 91.224; m.p. about 1,852℃; b.p. 4,377℃; sp. gr. 6.5 at 20℃; valence +2, +3, or +4. Zirconium is a very ...

Meyerhof, Otto

(Encyclopedia)Meyerhof, Otto ôˈtō mīˈərhōf [key], 1884–1951, American physiologist, b. Germany, M.D. Heidelberg, 1909. He was professor at the Univ. of Kiel (1912–24) and at the Univ. of Berlin and direc...

mercuric chloride

(Encyclopedia)mercuric chloride or mercury (II) chloride, chemical compound, HgCl2, a white powder of colorless rhombohedral crystals, somewhat soluble in water. It is also called bichloride of mercury or corrosive...

Mariupol

(Encyclopedia)Mariupol zhdänˈəf [key], city (1989 pop. 520,000), SE Ukraine, on the Sea of Azov and at the mouth of the Kalmius River. A seaport and railroad terminus, Mariupol is also an iron and steel center w...

Krebs, Sir Hans Adolf

(Encyclopedia)Krebs, Sir Hans Adolf krĕbz, krĕps [key], 1900–1981, English biochemist, b. Germany, M.D. Univ. of Hamburg, 1925. He taught at Cambridge and at the Univ. of Sheffield and after 1954 was professor ...

kaolinite

(Encyclopedia)kaolinite kāˈəlĭnīt [key], clay mineral crystallizing in the monoclinic system and forming the chief constituent of china clay and kaolin. It is a hydrous aluminum silicate commonly formed by the...

National Institute of Standards and Technology

(Encyclopedia)National Institute of Standards and Technology, governmental agency within the U.S. Dept. of Commerce with the mission of “working with industry to develop and apply technology, measurements, and st...

Haworth, Sir Walter Norman

(Encyclopedia)Haworth, Sir Walter Norman, 1883–1950, British chemist, Ph.D. Univ. of Göttingen, 1911. Haworth held academic posts at Imperial College of Science and Technology in London (1911–12), the Univ. of...

Haber, Fritz

(Encyclopedia)Haber, Fritz häˈbər [key], 1868–1934, German chemist. He was a professor of physical chemistry at Karlsruhe and became director of the Kaiser Wilhelm Institute at Dahlem in 1911. During World War...