PTL:Thulium
From ChemEd Collaborative
| Symbol: | Tm |
|---|---|
| Atomic Number: | 69 |
| Atomic Weight: | 168.93421(3) |
| Electron Configuration: | [Xe] 4f13 6s2 |
| Atomic Radius: | 174.6pm |
| Melting Point: | 1545°C |
| Boiling Point: | 1950°C |
| Heat of Fusion: | 16.84kJ/mol |
| Heat of Vaporization: | 191kJ/mol |
| Specific Heat Capacity: | 0.16J/gK |
Thulium is a member of the lanthanide series of elements, which stretches from lanthanum (La) to lutetium (Lu).
Contents |
Discovered
The element was discovered by Cleve, who also discovered holmium, in 1879.
Name
The element was named for Thule, the ancient name for Scandanavia.
Characteristics
Thulium is the least abundant in the earth's crust of the naturally occurring lanthanides.
In the solid state, the metal has a hexagonal closest packed structure.
The metal is silvery and more dense than any of the preceding lanthanides. It is also soft and can be cut with a knife. It is reasonably stable in air, but it will react with air and moisture.
Prepared
Like a number of the other lanthanides, thulium can be obtained from the mineral monazite [(Ce,Y,La,Nd,Th)PO4], a mixture of the phosphates of Ca, Th, and Ce and other lanthanides.
Uses
Owing to the high cost of thulium, it has found few uses. One use of a radioactive isotope of Tm is as a radiation source in portable X-ray equipment.
Emission Spectra
This is the emission spectra for Thulium.
