Beryllium vs Einsteinium

PropertyBe BerylliumEs Einsteinium
Atomic number499
SymbolBeEs
NameBerylliumEinsteinium
Categoryalkaline-earth-metalactinide
Standard Atomic Weight9.012183 u252 u
Period27
Group2N/A
Blockss
Phase at STPsolidsolid
Electron configuration[He]2s2[Rn]7s25f11
Oxidation states[0, 1, 2][2, 3, 4]
Electronegativity (Pauling)1.571.3
Electron affinity-0.52 eV-0.3 eV
Density1850 kg/m³8840 kg/m³
Melting point1286.85 °C859.85 °C
Boiling point2470.85 °C-273.15 °C
Discovery year17971952