Radium vs Einsteinium

PropertyRa RadiumEs Einsteinium
Atomic number8899
SymbolRaEs
NameRadiumEinsteinium
Categoryalkaline-earth-metalactinide
Standard Atomic Weight226 u252 u
Period77
Group2N/A
Blockss
Phase at STPsolidsolid
Electron configuration[Rn]7s2[Rn]7s25f11
Oxidation states[2][2, 3, 4]
Electronegativity (Pauling)0.91.3
Electron affinity0.096 eV-0.3 eV
Density5000 kg/m³8840 kg/m³
Melting point699.85 °C859.85 °C
Boiling point1139.85 °C-273.15 °C
Discovery year18981952