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lawrencium

(Encyclopedia)lawrencium, artificially produced radioactive chemical element; symbol Lr; at. no. 103; mass number of most stable isotope 262; m.p. about 1,627℃; b.p. and sp. gr. unknown; valence +3. Lawrencium is...

l-dopa

(Encyclopedia)l-dopa ĕl-dōˈpə [key], drug used to alleviate some of the symptoms of Parkinson's disease, particularly trembling, rigidity, and slow movements; the drug is also called levodopa. Parkinson's disea...

antidiuretic hormone

(Encyclopedia)antidiuretic hormone ănˌtēdīyo͞orĕtˈĭk [key], polypeptide hormone secreted by the posterior pituitary gland. Its principal action is to regulate the amount of water excreted by the kidneys. An...

curare

(Encyclopedia)curare kyo͝orärˈē [key], any of a variety of substances originally used as arrow poisons by Native South Americans in hunting and in warfare. The main active substance of curare, tubocurarine, is ...

Cyrankiewicz, Józef

(Encyclopedia)Cyrankiewicz, Józef yo͞oˈzĕf tsĭränkyāˈvĭch [key], 1911–89, Polish political leader. Active in the Polish resistance after the German invasion in 1939, he was arrested in 1941 and spent the...

barium

(Encyclopedia)barium bârˈēəm [key] [Gr.,=heavy], metallic chemical element; symbol Ba; at. no. 56; at. wt. 137.327; m.p. 725℃; b.p. 1,640℃; sp. gr. 3.5 at 20℃; valence +2. Barium is a soft, silver-white, ...

bubble chamber

(Encyclopedia)bubble chamber, device for detecting charged particles and other radiation by means of tracks of bubbles left in a chamber filled with liquid hydrogen or other liquefied gas. It was invented in 1952 b...

electron

(Encyclopedia)electron, elementary particle carrying a unit charge of negative electricity. Ordinary electric current is the flow of electrons through a wire conductor (see electricity). The electron is one of the ...

Morley, Edward Williams

(Encyclopedia)Morley, Edward Williams, 1838–1923, American scientist, b. Newark, N.J., grad. Williams College, 1860. From 1869 to 1906 he was professor of chemistry at Western Reserve College (now Case Western Re...

Jovian planets

(Encyclopedia)Jovian planets, the planets Jupiter, Saturn, Uranus, and Neptune. They are all larger and more massive than the earth. Since they rotate faster, they are more flattened at the poles than are the terre...