Niobium vs Einsteinium

PropertyNb NiobiumEs Einsteinium
Atomic number4199
SymbolNbEs
NameNiobiumEinsteinium
Categorytransition-metalactinide
Standard Atomic Weight92.90637 u252 u
Period57
Group5N/A
Blockss
Phase at STPsolidsolid
Electron configuration[Kr]5s14d4[Rn]7s25f11
Oxidation states[-3, -1, 0, 1, 2, 3, 4, 5][2, 3, 4]
Electronegativity (Pauling)1.61.3
Electron affinity0.893 eV-0.3 eV
Density8570 kg/m³8840 kg/m³
Melting point2476.85 °C859.85 °C
Boiling point4743.85 °C-273.15 °C
Discovery year18011952