PERIODIC ELEMENT
Os (Osmium)





Atomic number : 76
Atomic mass : 190.2 g.mol-1
Electronegativity according to Pauling : 2.2
Density : 22.5 g.cm-3 at 20 °C
Melting point : 3045 °C
Boiling point : 5027 °C
Vanderwaals radius : 0.136 nm
Ionic radius : 0.637 nm (+4)
Isotopes : 13
Electronic shell : [Xe] 4f14 5d- 6s2
Energy of first ionisation : 838 kJ.mol-1
Standard Potential : + 0.85 V (Os2+ / Os)
Discovered by : Smithson Tennant in 1803
 
Atomic Structure Uses (tip gold pen points, instrument pivots, electrical light filaments)