Boron vs Thallium

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PropertyB BoronTl Thallium
Atomic number581
SymbolBTl
NameBoronThallium
Categorymetalloidpost-transition-metal
Standard Atomic Weight10.8135 u204.3835 u
Period26
Group1313
Blockpp
Phase at STPsolidsolid
Electron configuration[He]2s22p1[Xe]6s24f145d106p1
Oxidation states[-5, -1, 0, 1, 2, 3][-5, -2, -1, 1, 2, 3]
Electronegativity (Pauling)2.041.62
Electron affinity0.27972 eV0.377 eV
Density2370 kg/m³1.180000e+4 kg/m³
Melting point2074.85 °C303.85 °C
Boiling point3999.85 °C1472.85 °C
Discovery year18081861