Cerium vs Francium

PropertyCe CeriumFr Francium
Atomic number5887
SymbolCeFr
NameCeriumFrancium
Categorylanthanidealkali-metal
Standard Atomic Weight140.116 u223 u
Period67
GroupN/A1
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f15d1[Rn]7s1
Oxidation states[1, 2, 3, 4][1]
Electronegativity (Pauling)1.120.7
Electron affinity0.955 eV0.491 eV
Density6770 kg/m³1870 kg/m³
Melting point797.85 °C26.85 °C
Boiling point3423.85 °C-273.15 °C
Discovery year18011939