Cerium vs Actinium

PropertyCe CeriumAc Actinium
Atomic number5889
SymbolCeAc
NameCeriumActinium
Categorylanthanideactinide
Standard Atomic Weight140.116 u227 u
Period67
GroupN/AN/A
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f15d1[Rn]7s26d1
Oxidation states[1, 2, 3, 4][3]
Electronegativity (Pauling)1.121.1
Electron affinity0.955 eV0.35 eV
Density6770 kg/m³1.007000e+4 kg/m³
Melting point797.85 °C1050.85 °C
Boiling point3423.85 °C3197.85 °C
Discovery year18011899