Europium vs Erbium

PropertyEu EuropiumEr Erbium
Atomic number6368
SymbolEuEr
NameEuropiumErbium
Categorylanthanidelanthanide
Standard Atomic Weight151.964 u167.259 u
Period66
GroupN/AN/A
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f7[Xe]6s24f12
Oxidation states[0, 2, 3][0, 1, 2, 3]
Electronegativity (Pauling)N/A1.24
Electron affinity0.116 eV0.312 eV
Density5240 kg/m³9070 kg/m³
Melting point821.85 °C1528.85 °C
Boiling point1528.85 °C2867.85 °C
Discovery year18961843