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technetium

(Encyclopedia)technetium tĕknēˈshēəm [key] [Gr. technetos=artificial], artificially produced radioactive chemical element; symbol Tc; at. no. 43; mass no. of most stable isotope 98; m.p. 2,200℃; b.p. 4,877�...

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, ...

nitrate

(Encyclopedia)nitrate, chemical compound containing the nitrate (NO3) radical. Nitrates are salts or esters of nitric acid, HNO3, formed by replacing the hydrogen with a metal (e.g., sodium or potassium) or a radic...

flute

(Encyclopedia)flute, in music, generic term for such wind instruments as the fife, the flageolet, the panpipes, the piccolo, and the recorder. The tone of all flutes is produced by an airstream directed against an ...

Helena

(Encyclopedia)Helena. 1 City (2020 pop. 20,633), Jefferson and Shelby cos., central Ala.; inc. 1877. White settlers began to occupy the area after the War of ...

Cádiz

(Encyclopedia)Cádiz käˈdēth [key], city, capital of Cádiz prov., SW Spain, in Andalusia, on the Bay of...

cesium

(Encyclopedia)cesium sēˈzēəm [key] [Lat.,=bluish gray], a metallic chemical element; symbol Cs; at. no. 55; at. wt. 132.90545; m.p. 28.4℃; b.p. 669.3℃; sp. gr. 1.873 at 20℃; valence +1. Cesium is a ductil...

Persian art and architecture

(Encyclopedia)Persian art and architecture, works of art and structures produced in the region of Asia traditionally known as Persia and now called Iran. Bounded by fierce mountains and deserts, the high plateau of...

soap plant

(Encyclopedia)soap plant, any of various plants having cleansing properties. A few are of commercial importance, but most soap plants are used locally, as in early times, for toilet and laundry purposes. The soapba...

tin

(Encyclopedia)tin, metallic chemical element; symbol Sn [Lat. stannum]; at. no. 50; at. wt. 118.710; m.p. 231.9681℃; b.p. 2,270℃; sp. gr. 5.75 (gray), 7.3 (white); valence +2 or +4. Tin exhibits allotropy; abov...