Osmium vs Fermium

PropertyOs OsmiumFm Fermium
Atomic number76100
SymbolOsFm
NameOsmiumFermium
Categorytransition-metalactinide
Standard Atomic Weight190.23 u257 u
Period67
Group8N/A
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f145d6[Rn] 5f12 7s2
Oxidation states[-4, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8][2, 3]
Electronegativity (Pauling)2.21.3
Electron affinity1.1 eV0.339 eV
Density2.258720e+4 kg/m³9700 kg/m³
Melting point3032.85 °C1526.85 °C
Boiling point5011.85 °C-273.15 °C
Discovery year18031952