Niobium vs Erbium

PropertyNb NiobiumEr Erbium
Atomic number4168
SymbolNbEr
NameNiobiumErbium
Categorytransition-metallanthanide
Standard Atomic Weight92.90637 u167.259 u
Period56
Group5N/A
Blockss
Phase at STPsolidsolid
Electron configuration[Kr]5s14d4[Xe]6s24f12
Oxidation states[-3, -1, 0, 1, 2, 3, 4, 5][0, 1, 2, 3]
Electronegativity (Pauling)1.61.24
Electron affinity0.893 eV0.312 eV
Density8570 kg/m³9070 kg/m³
Melting point2476.85 °C1528.85 °C
Boiling point4743.85 °C2867.85 °C
Discovery year18011843