Holmium (Ho)

Holmium is the 67th element in the periodic table and has a symbol of Ho and atomic number of 67. It has an atomic weight of 164.93033 and a mass number of 165. Holmium has sixty-seven protons and ninety-eight neutrons in its nucleus, and sixty-seven electrons in six shells. It is located in group Lanthanides, period six and block f of the periodic table. Relatively soft and malleable silvery-white metallic element, which is stable in dry air at room temperature. It oxidizes in moist air and at high temperatures. It belongs to the lanthanoids. A rare-earth metal, it is found in the minerals monazite and gadolinite. It possesses unusual magnetic properties. One natural isotope, Ho-165 exists, six radioisotopes exist, the most stable being Ho-163 with a half-life of 4570 years. Holmium is used in some metal alloys, it is also said to stimulate the metabolism. Discovered by Per Theodor Cleve and J.L. Soret in Switzerland in 1879. The name homium comes from the Greek word Holmia which means Sweden. While all holmium compounds should be considered highly toxic, initial evidence seems to indicate that they do not pose much danger. The metal's dust however, is a fire hazard.