Francium vs Americium

PropertyFr FranciumAm Americium
Atomic number8795
SymbolFrAm
NameFranciumAmericium
Categoryalkali-metalactinide
Standard Atomic Weight223 u243 u
Period77
Group1N/A
Blockss
Phase at STPsolidsolid
Electron configuration[Rn]7s1[Rn]7s25f7
Oxidation states[1][2, 3, 4, 5, 6, 7]
Electronegativity (Pauling)0.71.3
Electron affinity0.491 eV0.1 eV
Density1870 kg/m³1.369000e+4 kg/m³
Melting point26.85 °C1175.85 °C
Boiling point-273.15 °C2010.85 °C
Discovery year19391944