Thorium
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Description
A soft, silvery radioactive metallic element. Thorium was discovered by Baron Berzelius, a Swedish chemist in 1929. It has an abundance of about 8-15 ppm in the earth's crust and occurs mainly in the minerals thorite, thorianite, orangite, yttrocrasite, and monazite sand. Metallic thorium is a malleable and ductile. It turns dark and oxidizes in air. Thorium is used in the manufacture of ceramics, sun lamps, photoelectric cells, incandescent gaslight mantles, and welding electrodes.
Synonyms and Related Terms
Th
Risks
- Powder is flammable and explosive.
- Radioactive.
- IBI Labs: [https://ibilabs.com/msds/thorium-compounds-msds/thorium-metal-msds/ SDS}
Physical and Chemical Properties
Soluble in acids. Insoluble in water, alkalis.
| Composition | Th (atomic no. 90) |
|---|---|
| CAS | 7440-29-1 |
| Melting Point | 1750-1800 C |
| Density | 11.0-11.7 g/ml |
| Molecular Weight | atomic wt = 232.038 |
| Boiling Point | 4700-4800 C |
Resources and Citations
- G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 807
- Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976
- Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997
- The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998
- Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
- The Merck Index, Martha Windholz (ed.), Merck Research Labs, Rahway NJ, 10th edition, 1983 Comment: entry 9514