Rubidium vs Barium

PropertyRb RubidiumBa Barium
Atomic number3756
SymbolRbBa
NameRubidiumBarium
Categoryalkali-metalalkaline-earth-metal
Standard Atomic Weight85.4678 u137.327 u
Period56
Group12
Blockss
Phase at STPsolidsolid
Electron configuration[Kr]5s1[Xe]6s2
Oxidation states[-1, 1][1, 2]
Electronegativity (Pauling)0.820.89
Electron affinity0.4859 eV0.1447 eV
Density1530 kg/m³3620 kg/m³
Melting point39.31 °C726.85 °C
Boiling point687.85 °C1896.85 °C
Discovery year18611808