Europium vs Actinium

PropertyEu EuropiumAc Actinium
Atomic number6389
SymbolEuAc
NameEuropiumActinium
Categorylanthanideactinide
Standard Atomic Weight151.964 u227 u
Period67
GroupN/AN/A
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f7[Rn]7s26d1
Oxidation states[0, 2, 3][3]
Electronegativity (Pauling)N/A1.1
Electron affinity0.116 eV0.35 eV
Density5240 kg/m³1.007000e+4 kg/m³
Melting point821.85 °C1050.85 °C
Boiling point1528.85 °C3197.85 °C
Discovery year18961899