Erbium vs Rutherfordium

PropertyEr ErbiumRf Rutherfordium
Atomic number68104
SymbolErRf
NameErbiumRutherfordium
Categorylanthanidetransition-metal
Standard Atomic Weight167.259 u263 u
Period67
GroupN/A4
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f12[Rn]7s25f146d2
Oxidation states[0, 1, 2, 3][3, 4]
Electronegativity (Pauling)1.24N/A
Electron affinity0.312 eV0.65 eV
Density9070 kg/m³2.330000e+4 kg/m³
Melting point1528.85 °C2126.85 °C
Boiling point2867.85 °C5526.85 °C
Discovery year18431964