Niobium vs Radium

PropertyNb NiobiumRa Radium
Atomic number4188
SymbolNbRa
NameNiobiumRadium
Categorytransition-metalalkaline-earth-metal
Standard Atomic Weight92.90637 u226 u
Period57
Group52
Blockss
Phase at STPsolidsolid
Electron configuration[Kr]5s14d4[Rn]7s2
Oxidation states[-3, -1, 0, 1, 2, 3, 4, 5][2]
Electronegativity (Pauling)1.60.9
Electron affinity0.893 eV0.096 eV
Density8570 kg/m³5000 kg/m³
Melting point2476.85 °C699.85 °C
Boiling point4743.85 °C1139.85 °C
Discovery year18011898