Osmium (Os) is a chemical element with atomic number (Z) 76, group 8, period 6, and atomic weight 190.23. The Osmium (Os) is lustrous, silvery metal that is the densest metal known, and Osmium powder reacts slowly with the oxygen of the air and gives off detectable amounts of osmium tetroxide vapour, used in a few alloys and in industry as a catalyst. (Refer to the Chemical Element; Periodic Table)
