Francium vs Einsteinium

PropertyFr FranciumEs Einsteinium
Atomic number8799
SymbolFrEs
NameFranciumEinsteinium
Categoryalkali-metalactinide
Standard Atomic Weight223 u252 u
Period77
Group1N/A
Blockss
Phase at STPsolidsolid
Electron configuration[Rn]7s1[Rn]7s25f11
Oxidation states[1][2, 3, 4]
Electronegativity (Pauling)0.71.3
Electron affinity0.491 eV-0.3 eV
Density1870 kg/m³8840 kg/m³
Melting point26.85 °C859.85 °C
Boiling point-273.15 °C-273.15 °C
Discovery year19391952