Rhenium vs Osmium

Side-by-side comparison of Rhenium (Re, element 75) and Osmium (Os, element 76) by atomic structure and physical properties.

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PropertyRe Rhenium Os Osmium
Atomic number7576
SymbolReOs
NameRheniumOsmium
Categorytransition-metaltransition-metal
Standard Atomic Weight186.207 u190.23 u
Period66
Group78
Blockdd
Phase at STPSolidSolid
Electron configuration[Xe]4f145d56s2[Xe]4f145d66s2
Oxidation states[-3, -1, 0, 1, 2, 3, 4, 5, 6, 7][-4, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8]
Electronegativity (Pauling)1.92.2
Electron affinity0.060396 eV1.077661 eV
Density2.08e+4 kg/m³2.25872e+4 kg/m³
Melting point3185.85 °C3032.85 °C
Boiling point5595.85 °C5011.85 °C
Discovery year19251803

Key Differences

PropertyRe RheniumOs Osmium
Standard Atomic Weight186.207 u ↓ lower190.23 u ↑ higher
Density2.08e+4 kg/m³ ↓ lower2.25872e+4 kg/m³ ↑ higher
Melting point3185.85 °C ↑ higher3032.85 °C ↓ lower
Boiling point5595.85 °C ↑ higher5011.85 °C ↓ lower
Electronegativity (Pauling)1.9 ↓ lower2.2 ↑ higher
Electron affinity0.060396 eV ↓ lower1.077661 eV ↑ higher
Group7 8
Electron configuration[Xe]4f145d56s2 [Xe]4f145d66s2
Discovery year1925 1803