An Etymological Dictionary of Astronomy and Astrophysics

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فرهنگ ریشه‌شناختی اخترشناسی-اخترفیزیک

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thorium
  توریوم  
toriom (#)
Fr.: thorium  

A soft, ductile, lustrous, silver-white, → radioactive metal; symbol Th. → Atomic number 90; → atomic weight 232.0381; → melting point about 1,750 °C;
→ boiling point about 4,790 °C; → specific gravity 11.7 at 20 °C. It was discovered in the mineral thorite (ThSiO4) by the Swedish chemist Jons Jacob Berzelius in 1828. It was first isolated by the chemists D. Lely Jr. and L. Hamburger in 1914.

Thorium-232 is a → fertile isotope, naturally occurring, from which the → fissile isotope uranium-233 can be bred.

See also: From Thor, the “Scandinavian god of thunder.”