Holmium

=**Holmium**=

Holmium was discovered by Per Theodor Cleve, a Swedish chemist, in 1879. Cleve used the same method Carl Gustaf Mosander used to discover lanthanum, erbium and terbium, he looked for impurities in the oxides of other rare earth elements. He started with erbia, the oxide of erbium (Er2O3), and removed all of the known contaminants. After further processing, he obtained two new materials, one brown and the other green. Cleve named the brown material holmia and the green material thulia. Holmia is the oxide of the element holmium and thulia is the oxide of the element thulium. Holmium's absorption spectrum was observed earlier that year by J. L. Soret and M. Delafontaine, Swiss chemists. Today, holmium is primarily obtained through an ion exchange process from monazite sand ((Ce, La, Th, Nd, Y)PO4), a material rich in rare earth elements that can contain as much as 0.05% holmium. Holmium has no commercial applications, although it has unusual magnetic properties that could be exploited in the future. Holmium forms no commercially important compounds. Some of holmium's compounds include: holmium oxide (Ho2O3), holmium fluoride (HoF3) and holmium iodide (HoI3).
 * Atomic Number:** 67
 * Atomic Weight:** 164.93032
 * Melting Point:** 1747 K (1474°C or 2685°F)
 * Boiling Point:** 2973 K (2700°C or 4892°F)
 * Density:** 8.80 grams per cubic centimeter
 * Phase at Room Temperature:** Solid
 * Element Classification:** Metal
 * Period Number:** 6 **Group Number:** none **Group Name:** Lanthanide
 * What's in a name?** From the Latin word for the city of Stockholm, **Holmia**.
 * Say what?** Holmium is pronounced as **HOHL-mee-em**.
 * History and Uses:**
 * Estimated Crustal Abundance:** 1.3 milligrams per kilogram
 * Estimated Oceanic Abundance:** 2.2×10-7 milligrams per liter
 * Number of Stable Isotopes:** 1
 * Ionization Energy:** 6.022 eV
 * Oxidation State:** +3

Characteristics
Elemental holmium is a relatively soft and malleable silvery-white metal. It is too reactive to be found uncombined in nature, but when isolated, is relatively stable in dry air at room temperature. However, it reacts with water and rusts readily, and will also burn in air when heated. Holmium is found in the minerals monazite and gadolinite, and is usually commercially extracted from monazite using ion exchange techniques. Its compounds in nature, and in nearly all of its laboratory chemistry, are trivalently oxidized, containing Ho(III) ions. Trivalent holmium ions have fluorescent properties similar to many other rare earth ions (while yielding their own set of unique emission light lines), and holmium ions are thus used in the same way as some other rare earths in certain laser and glass colorant applications. Holmium has the highest magnetic strength of any element and therefore is used for the polepieces of the strongest static magnets. Because holmium strongly absorbs neutrons, it is also used in nuclear control rods.

Atomic Structure

 * [[image:http://www.chemicalelements.com/bohr/b0067.gif width="355" height="353"]] ||  ||   ||

Isotopes

 * ** Isotope ** || ** Half Life ** ||
 * Ho-163 || 4570.0 years ||
 * Ho-165 || Stable ||
 * Ho-166 || 1.1 days ||
 * Ho-166m || 1200.0 years ||

Facts

 * Date of Discovery:** 1878 **Discoverer:** J.L. Soret **Name Origin:** Form the Latin word //Holmia// (Stockholm) **Uses:** nuclear reactors **Obtained From:** gadolinite