Thulium
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Description
A rare-earth element of the yttrium group. Thulium was discovered in 1879 by P.T.Cleve, a Swedish chemist. It has an abundance of 0.48 ppm in the earth's crust. Thulium occurs in rare earth minerals such as euxenite, ytterspar, sipylite and gadolinite. It is a silvery-white, metal that is easily worked. Thulium is used as a radioactive source in small, portable x-ray machines.
Synonyms and Related Terms
Tm
Risks
- Dust is flammable.
- Sensitive to moisture and air.
- Fisher Scientific: MSDS
Physical and Chemical Properties
Soluble in dilute acids. Reacts slowly with water.
| Composition | Tm (atomic no. 69) |
|---|---|
| CAS | 7440-30-4 |
| Melting Point | 1545-1550 C |
| Density | 9.318 g/ml |
| Molecular Weight | atomic wt = 168.934 |
| Boiling Point | 1725-1727 C |
Resources and Citations
- G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 179
- Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
- 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 Merck Index, Martha Windholz (ed.), Merck Research Labs, Rahway NJ, 10th edition, 1983 Comment: entry 9535
- The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998