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roentgenium

(Encyclopedia)roentgenium, artificially produced radioactive chemical element; symbol Rg; at. no. 111; mass number of most stable isotope 280; m.p., b.p., sp. gr., and valence unknown. Situated in Group 11 of the p...

Watkins, Carleton Eugene

(Encyclopedia)Watkins, Carleton Eugene, 1829–1916, America's premier 19th-century landscape photographer, b. Oneonta, N.Y. Watkins created images that helped define the American West for his contemporaries and th...

Krasnoyarsk Territory

(Encyclopedia)Krasnoyarsk Territory, administrative division (1989 pop. 3,595,000), c.928,000 sq mi (2,403,520 sq km), central Siberian Russia, extending from the Sayan Mts. and the Minusinsk basin in the south acr...

dysprosium

(Encyclopedia)dysprosium dĭsprōˈzēəm [key] [Gr.,=hard to get at], metallic chemical element; symbol Dy; at. no. 66; at. wt. 162.500; m.p. 1,412℃; b.p. 2,562℃; sp. gr. 8.54 at 25℃; valence+3. Dysprosium i...

pyrite

(Encyclopedia)pyrite pīrīˈtēz, pə–, pīˈrīts [key], pale brass-yellow mineral, the bisulfide of iron, FeS2. It occurs most commonly in crystals (belonging to the isometric system and usually in the form of...

rhodium

(Encyclopedia)rhodium rōˈdēəm [key], metallic chemical element; symbol Rh; at. no. 45; at. wt. 102.90550; m.p. about 1,966℃; b.p. 3,727±100℃; sp. gr. 12.41 at 20℃; valence +2, +3, +4, +5, or +6. Rhodium ...

osmium

(Encyclopedia)osmium ŏzˈmēəm [key], metallic chemical element; symbol Os; at. no. 76; at. wt. 190.23; m.p. 3,045±30℃; b.p. 5,027±100℃; sp. gr. 22.57 at 20℃; valence usually +0 to +8. Osmium is a very ha...

synthetic elements

(Encyclopedia)synthetic elements, in chemistry, radioactive elements that were not discovered occurring in nature but as artificially produced isotopes. They are technetium (at. no. 43), which was the first element...

Labrador-Ungava

(Encyclopedia)Labrador-Ungava lăbˈrədôrˌ-əngāˈvə, –əngävˈə [key], peninsular region of E Canada, c.550,000 sq mi (1,424,500 sq km), bounded on the W by Hudson Bay, on the N by Hudson Strait and Ungav...

Murmansk

(Encyclopedia)Murmansk mo͝ormänskˈ [key], city (1989 pop. 468,000), capital of Murmansk region, NW European Russia, on the Kola Gulf of the Barents Sea. It is the terminus of the Northeast Passage and the world'...