Niobium vs Europium

PropertyNb NiobiumEu Europium
Atomic number4163
SymbolNbEu
NameNiobiumEuropium
Categorytransition-metallanthanide
Standard Atomic Weight92.90637 u151.964 u
Period56
Group5N/A
Blockss
Phase at STPsolidsolid
Electron configuration[Kr]5s14d4[Xe]6s24f7
Oxidation states[-3, -1, 0, 1, 2, 3, 4, 5][0, 2, 3]
Electronegativity (Pauling)1.6N/A
Electron affinity0.893 eV0.116 eV
Density8570 kg/m³5240 kg/m³
Melting point2476.85 °C821.85 °C
Boiling point4743.85 °C1528.85 °C
Discovery year18011896