Niobium vs Thallium

PropertyNb NiobiumTl Thallium
Atomic number4181
SymbolNbTl
NameNiobiumThallium
Categorytransition-metalpost-transition-metal
Standard Atomic Weight92.90637 u204.3835 u
Period56
Group513
Blocksp
Phase at STPsolidsolid
Electron configuration[Kr]5s14d4[Xe]6s24f145d106p1
Oxidation states[-3, -1, 0, 1, 2, 3, 4, 5][-5, -2, -1, 1, 2, 3]
Electronegativity (Pauling)1.61.62
Electron affinity0.893 eV0.377 eV
Density8570 kg/m³1.180000e+4 kg/m³
Melting point2476.85 °C303.85 °C
Boiling point4743.85 °C1472.85 °C
Discovery year18011861