Strontium vs Einsteinium

PropertySr StrontiumEs Einsteinium
Atomic number3899
SymbolSrEs
NameStrontiumEinsteinium
Categoryalkaline-earth-metalactinide
Standard Atomic Weight87.62 u252 u
Period57
Group2N/A
Blockss
Phase at STPsolidsolid
Electron configuration[Kr]5s2[Rn]7s25f11
Oxidation states[1, 2][2, 3, 4]
Electronegativity (Pauling)0.951.3
Electron affinity0.052 eV-0.3 eV
Density2640 kg/m³8840 kg/m³
Melting point776.85 °C859.85 °C
Boiling point1381.85 °C-273.15 °C
Discovery year17921952