My Saved Article
For eye-safe lasers | Atomic Number: | 67 | Atomic Symbol: | Ho | | Atomic Weight: | 164.9304 | Electron Configuration: | 2-8-29-8-2 | | Shells: | 2,8,18,29,8,2 | Filling Orbital: | 4f11 | | Melting Point: | 1470oC | Boiling Point: | 2720oC | | Description: | Silver colored rare earth metal. |
History(L. Holmia, for Stockholm). The special absorption bands of
holmium were noticed in 1878 by the Swiss chemists Delafontaine and Soret, who
announced the existence of an "Element X." Cleve, of Sweden, later independently
discovered the element while working on erbia earth. The element is named after
cleve's native city. Holmia, the yellow oxide, was prepared by Homberg in 1911.
OccurenceHolmium occurs in gadolinite, monazite, and in other
rare-earth minerals. It is commercially obtained from monazite, occurring in
that mineral to the extent of about 0.05%. It has been isolated by the reduction
of its anhydrous chloride or fluoride with calcium metal.
Properties- Pure holmium has a metallic to bright silver luster.
- It is relatively soft and malleable, and is stable in dry air at room
temperature, but rapidly oxidizes in moist air and at elevated temperatures.
- The metal has unusual magnetic properties.
- Few uses have yet been found for the element.
- The element, as with other rare earths, seems to have a low acute toxic
rating.
CostsThe price of 99+% holmium metal is about $10/g.
|
|
|