Holmium

Bryan Moore Holymium S*** November 13,2009

Name: Holmium Symbol: Ho Atomic #: 67 Atomic weight: 164.93032 Standard state: solid at 298 K Group Name: Lanthanoid Period on periodic table: 6 Block in periodic table: f-block Color: silvery white Classification: Metallic Protons: 67excelchemistry - Holmium Neutrons: 98 Electrons: 67 Electron Configuration: [Xe],6s2 =Physical Properties:= Holmium is a relatively soft and malleable element that is fairly corrosion-resistant and stable in dry air at standard temperature and pressure. In moist air and at higher temperatures, however, it quickly oxidizes, forming a yellowish oxide. In pure form, holmium possesses a metallic, bright silvery luster. = = =Chemical Properties:= Holmium metal tends to be stable at room temperature. In moist air and at higher temperatures, it becomes more reactive. For example, it combines with oxygen to form holmium oxide.

=History:= Holmium (//Holmia//, Latin name for Stockholm) was discovered by Marc Delafontaine and Jacques-Louis Soret in 1878 who noticed the aberrant spectrographic absorption bands of the then-unknown element (they called it "Element X"). Later in 1878, Per Teodor Cleve independently discovered the element while he was working on erbia earth.

=Isotopes:= Natural holmium contains one stable isotope, holmium-165. Some synthetic radioactive isotopes are known, the most stable one is holmium-163, with a half life of 4570 years. All other radioisotopes have ground-state half lives not greater than 1.117 days, and most have half lives under 3 hours. =Uses:= Because of its magnetic properties, holmium has been used to create the strongest artificially-generated magnetic fields when placed within high-strength magnets as a magnetic pole piece (also called a magnetic flux concentrator). =Common Forms:= Holmium is one of the rarer of the rare-earth elements but is, nevertheless, 20 times more abundant than silver. Like all other rare earths, holmium is not naturally found as free element. It is found in minerals such as monazite and bastanasite, even if it is just a minor components of such ores.

=Bibliography:= http://www.lenntech.com/periodic/elements/ho.htm http://www.chemistryexplained.com/elements/C-K/Holmium.html http://www.webelements.com/holmium/ http://en.wikipedia.org/wiki/Holmium