Rubidium vs Thallium

PropertyRb RubidiumTl Thallium
Atomic number3781
SymbolRbTl
NameRubidiumThallium
Categoryalkali-metalpost-transition-metal
Standard Atomic Weight85.4678 u204.3835 u
Period56
Group113
Blocksp
Phase at STPsolidsolid
Electron configuration[Kr]5s1[Xe]6s24f145d106p1
Oxidation states[-1, 1][-5, -2, -1, 1, 2, 3]
Electronegativity (Pauling)0.821.62
Electron affinity0.4859 eV0.377 eV
Density1530 kg/m³1.180000e+4 kg/m³
Melting point39.31 °C303.85 °C
Boiling point687.85 °C1472.85 °C
Discovery year18611861