Ogunyemi,+Felisa

__Iridium __ __The Proerties of Iridium __ The proerties of iridium(Ir) are the atomic number is 77. The atomic mass is 192.217.the numbers of protons and electons are77. The number of neutrons are 115. It has a boiling point of 4521.0 degrees C and it has a melting point 4527.0 degrees C. It is a transition metal and has the color of silver/white. The irdium is verybrittle and extermatly hard.The crystal **structure is cubic. It would give of a high pitch scream when bent. ** __The Common uses of Iridium __ Thay are used for cell phone and the also help satellites work. __Photo __ __References __ 1. [] 2. []
 * __The History of Iridium __**
 * Iridium was discovered in the year of 1804. Iridium was discoveredby **British chemist by the name of Smithson Tennant(1761-1815). Analyzed the insoluble residue and concluded that it must contain a new metal . In its chemical compounds it forms tetravalent and trivalent salts. It is an extremely rare metal, ranking 77th in order of abundance of the elements in the crust of the earth; iridium is found in alluvial deposits alloyed with platinum as platiniridium and with osmium as osmiridium.