Lutetium vs Francium

PropertyLu LutetiumFr Francium
Atomic number7187
SymbolLuFr
NameLutetiumFrancium
Categorylanthanidealkali-metal
Standard Atomic Weight174.9668 u223 u
Period67
Group31
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f145d1[Rn]7s1
Oxidation states[0, 1, 2, 3][1]
Electronegativity (Pauling)1.270.7
Electron affinity0.346 eV0.491 eV
Density9840 kg/m³1870 kg/m³
Melting point1662.85 °C26.85 °C
Boiling point3401.85 °C-273.15 °C
Discovery year19071939