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lutetium

(Encyclopedia)lutetium, formerly lutecium both: lo͞otēˈshēəm [key], metallic chemical element; symbol Lu; atomic number 71; at. wt. 174.9668; m.p. about 1,663℃; b.p. about 3,395℃; sp. gr. 9.835 at 25℃; v...

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...

tellurium

(Encyclopedia)tellurium tĕlo͝orˈēəm [key] [Lat.,=earth], semimetallic chemical element; symbol Te; at. no. 52; at. wt. 127.60; m.p. 450℃; b.p. 990℃; sp. gr. 6.24 at 20℃; valence −2, +4, or +6. Telluriu...

thallium

(Encyclopedia)thallium thălˈēəm [key], metallic chemical element; symbol Tl; at. no. 81; interval in which at. wt. ranges 204.382–204.385; m.p. 303.5℃; b.p. about 1,457℃; sp. gr. 11.85 at 20℃; valence +...

District of Columbia, University of the

(Encyclopedia)District of Columbia, University of the, at Washington, D.C.; coeducational; land-grant and federally supported; est. 1976 with the merger of three existing colleges; predominantly African American. I...

Field of the Cloth of Gold

(Encyclopedia)Field of the Cloth of Gold, locality between Guines and Ardres, not far from Calais, in France, where in 1520 Henry VIII of England and Francis I of France met for the purpose of arranging an alliance...

Gloucester, Thomas of Woodstock, duke of

(Encyclopedia)Gloucester, Thomas of Woodstock, duke of, 1355–97, English nobleman; youngest son of Edward III. He was betrothed (1374) to Eleanor, heiress of Humphrey de Bohun, earl of Hereford, and became earl o...

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