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samarium

(Encyclopedia)samarium səmârˈēəm [key], metallic chemical element; symbol Sm; at. no. 62; at. wt. 150.36; m.p. 1,072℃; b.p. 1,791℃; sp. gr. 7.54 at 20℃; valence +2 or +3. Samarium is a lustrous silver-wh...

Sm

(Encyclopedia)Sm, symbol for the element samarium. ...

Boisbaudran, Paul Émile Lecoq de

(Encyclopedia)Boisbaudran, Paul Émile Lecoq de pôl āmēlˈ ləkôkˈ də bwäbōdräNˈ [key], 1838–1912, French discoverer of the elements gallium, samarium, and dysprosium. He also made contributions in the ...

lanthanide series

(Encyclopedia)lanthanide series, a series of metallic elements, included in the rare-earth metals, in Group 3 of the periodic table. Members of the series are often called lanthanides, although lanthanum (atomic nu...

promethium

(Encyclopedia)promethium prōmēˈthēəm [key], artificially produced radioactive chemical element; symbol Pm; at. no. 61; mass no. of most stable isotope 145; m.p. 1,042℃; b.p. 3,000℃ (estimated); sp. gr. unk...

dating

(Encyclopedia)dating, the determination of the age of an object, of a natural phenomenon, or of a series of events. There are two basic types of dating methods, relative and absolute. In relative dating, the tempor...

Elements (table)

(Encyclopedia)Elements 1 Parentheses indicate most stable isotope; brackets enclose lower and upper bounds of weight variation. ...

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