Columbia Encyclopedia

Search results

159 results found

lead, chemical element

(Encyclopedia)lead, metallic chemical element; symbol Pb [Lat. plumbum]; at. no. 82; at. wt. 207.2; m.p. 327.502℃; b.p. about 1,740℃; sp. gr. 11.35 at 20℃; valence +2 or +4. One of the oldest metals used by h...

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...

Free State

(Encyclopedia)Free State, formerly Orange Free State, province, 50,126 sq mi (129,825 sq km), E central South Africa. It was renamed Free State shortly after the 1994...

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...

Bohr, Niels Henrik David

(Encyclopedia)Bohr, Niels Henrik David bōr [key], 1885–1962, Danish physicist, one of the foremost scientists of modern physics. He studied at the Univ. of Copenhagen (Ph.D. 1911) and carried on research on the...

Sakha Republic

(Encyclopedia)Sakha Republic yəko͞oˈshēə [key], constituent republic (1995 pop. 1,035,000), c.1,200,000 sq mi (3,108,000 sq km), NE Siberian Russia. Yakutsk is the capital. The Sakha Republic is bounded in the...

Curie

(Encyclopedia)Curie kürēˈ [key], family of French scientists. Pierre Curie, 1859–1906, scientist, and his wife, Marie Sklodowska Curie, 1867–1934, chemist and physicist, b. Warsaw, are known for their work o...

metal

(Encyclopedia)metal, chemical element displaying certain properties by which it is normally distinguished from a nonmetal, notably its metallic luster, the capacity to lose electrons and form a positive ion, and th...

Guangdong

(Encyclopedia)Guangdong or Kwangtung both: gwängˈdo͝ongˈ [key], province, c.76,000 sq mi (196,891 s...

fluorine

(Encyclopedia)fluorine flo͞oˈərēn, –rĭn [key], gaseous chemical element; symbol F; at. no. 9; at. wt. 18.9984; m.p. −219.6℃; b.p. −188.14℃; density 1.696 grams per liter at STP; valence −1. Fluorin...