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isomer

(Encyclopedia)isomer īˈsəmər [key], in chemistry, one of two or more compounds having the same molecular formula but different structures (arrangements of atoms in the molecule). Isomerism is the occurrence of ...

Balkash, lake, Kazakhstan

(Encyclopedia)Balkash, lake, 6,562 sq mi (16,996 sq km), c.350 mi (560 km) long, maximum width c.45 mi (70 km), in E Kazakhstan. The lake, which has an average depth of 20 ft (6 m), stretches from the Kazakh Upland...

emetic

(Encyclopedia)emetic əmĕtˈĭk [key], substance that produces vomiting. Direct, or gastric, emetics, which act directly on the stomach, include syrup of ipecac, sulfate of zinc or copper, alum, ammonium carbonate...

Pinar del Rio, province, Cuba

(Encyclopedia)Pinar del Rio pēnärˈ dĕl rēˈō [key], province (1994 est. pop. 700,000), W Cuba, the westernmost province of Cuba. Pinar del Rio is the capital. The province, occupying a narrow area, has an irr...

Honshu

(Encyclopedia)Honshu hōnˈsho͞o [key], island , c.89,000 sq mi (230,510 sq km), central Japan. It is c.800 ...

Buchans

(Encyclopedia)Buchans, town, central Newfoundland, N.L., Canada, on Red Indian Lake. It has a large mine that yields lead, silver, zinc, and copper. ...

helium

(Encyclopedia)helium hēˈlēəm [key], gaseous chemical element; symbol He; at. no. 2; at. wt. 4.0026; m.p. below −272℃ at 26 atmospheres pressure; b.p. −268.934℃ at 1 atmosphere pressure; density 0.1785 g...

Np

(Encyclopedia)Np, symbol for element neptunium. ...

McMillan, Edwin Mattison

(Encyclopedia)McMillan, Edwin Mattison, 1907–91, American physicist, b. Redondo Beach, Calif., grad. California Institute of Technology, 1928, Ph.D. Princeton, 1932. On the faculty of the Univ. of California from...

absorption

(Encyclopedia)absorption [Lat.,=sucking from], taking of molecules of one substance directly into another substance. It is contrasted with adsorption, in which the molecules adhere only to the surface of the second...