Erbium vs Thorium

PropertyEr ErbiumTh Thorium
Atomic number6890
SymbolErTh
NameErbiumThorium
Categorylanthanideactinide
Standard Atomic Weight167.259 u232.0377 u
Period67
GroupN/AN/A
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f12[Rn]7s26d2
Oxidation states[0, 1, 2, 3][-1, 1, 2, 3, 4]
Electronegativity (Pauling)1.241.3
Electron affinity0.312 eV0.607 eV
Density9070 kg/m³1.172000e+4 kg/m³
Melting point1528.85 °C1749.85 °C
Boiling point2867.85 °C4787.85 °C
Discovery year18431828