Americium vs Rutherfordium

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PropertyAm AmericiumRf Rutherfordium
Atomic number95104
SymbolAmRf
NameAmericiumRutherfordium
Categoryactinidetransition-metal
Standard Atomic Weight243 u263 u
Period77
GroupN/A4
Blockss
Phase at STPsolidsolid
Electron configuration[Rn]7s25f7[Rn]7s25f146d2
Oxidation states[2, 3, 4, 5, 6, 7][3, 4]
Electronegativity (Pauling)1.3N/A
Electron affinity0.1 eV0.65 eV
Density1.369000e+4 kg/m³2.330000e+4 kg/m³
Melting point1175.85 °C2126.85 °C
Boiling point2010.85 °C5526.85 °C
Discovery year19441964