Polonium vs Astatine

Side-by-side comparison of Polonium (Po, element 84) and Astatine (At, element 85) by atomic structure and physical properties.

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PropertyPo Polonium At Astatine
Atomic number8485
SymbolPoAt
NamePoloniumAstatine
Categorymetalloidhalogen
Standard Atomic Weight209 u210 u
Period66
Group1617
Blockpp
Phase at STPSolidSolid
Electron configuration[Xe]4f145d106s26p4[Xe]4f145d106s26p5
Oxidation states[-2, 2, 4, 5, 6][-1, 1, 3, 5, 7]
Electronegativity (Pauling)22.2
Electron affinity1.4 eV2.391 eV
Density9320 kg/m³7000 kg/m³
Melting point253.85 °C301.85 °C
Boiling point961.85 °CN/A
Discovery year18981940

Key Differences

PropertyPo PoloniumAt Astatine
Standard Atomic Weight209 u ↓ lower210 u ↑ higher
Density9320 kg/m³ ↑ higher7000 kg/m³ ↓ lower
Melting point253.85 °C ↓ lower301.85 °C ↑ higher
Electronegativity (Pauling)2 ↓ lower2.2 ↑ higher
Electron affinity1.4 eV ↓ lower2.391 eV ↑ higher
Group16 17
Categorymetalloid halogen
Electron configuration[Xe]4f145d106s26p4 [Xe]4f145d106s26p5
Discovery year1898 1940