Osmium (7440-04-2)

 Osmium ,its cas register number is 7440-04-2. It also can be called Osmium, elemental ;and Metallic osmium . It is the densest natural element, making it twice as dense as lead; and,  reacts with oxygen at room temperature forming volatile osmium tetroxide. Some osmium compounds are also converted to the tetroxide if oxygen is present. Osmium possesses quite remarkable chemical and physical properties.Only its two compounds have major applications: osmium tetroxide — for staining tissue in electron microscopy and the non-volatile osmates for organic oxidation reactions. It has seven naturally occurring isotopes, six of which are stable: ¹⁸⁴Os, ¹⁸⁷Os, ¹⁸⁸Os, ¹⁸⁹Os, ¹⁹⁰Os, and (most abundant) ¹⁹²Os. ¹⁸⁶Os .Within the Earth's crust, like iridium, Osmium (CAS NO.7440-04-2) is found at highest concentrations in three types of geologic structure: igneous deposits,impact craters, and deposits reworked from one of the former structures.

Reported in EPA TSCA Inventory.