Niobium vs Americium

PropertyNb NiobiumAm Americium
Atomic number4195
SymbolNbAm
NameNiobiumAmericium
Categorytransition-metalactinide
Standard Atomic Weight92.90637 u243 u
Period57
Group5N/A
Blockss
Phase at STPsolidsolid
Electron configuration[Kr]5s14d4[Rn]7s25f7
Oxidation states[-3, -1, 0, 1, 2, 3, 4, 5][2, 3, 4, 5, 6, 7]
Electronegativity (Pauling)1.61.3
Electron affinity0.893 eV0.1 eV
Density8570 kg/m³1.369000e+4 kg/m³
Melting point2476.85 °C1175.85 °C
Boiling point4743.85 °C2010.85 °C
Discovery year18011944