Arsenic vs Thallium

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PropertyAs ArsenicTl Thallium
Atomic number3381
SymbolAsTl
NameArsenicThallium
Categorymetalloidpost-transition-metal
Standard Atomic Weight74.921595 u204.3835 u
Period46
Group1513
Blockpp
Phase at STPsolidsolid
Electron configuration[Ar]4s23d104p3[Xe]6s24f145d106p1
Oxidation states[-3, -2, -1, 0, 1, 2, 3, 4, 5][-5, -2, -1, 1, 2, 3]
Electronegativity (Pauling)2.181.62
Electron affinity0.81 eV0.377 eV
Density5776 kg/m³1.180000e+4 kg/m³
Melting point816.85 °C303.85 °C
Boiling point613.85 °C1472.85 °C
Discovery year12501861