Zirconium vs Francium

PropertyZr ZirconiumFr Francium
Atomic number4087
SymbolZrFr
NameZirconiumFrancium
Categorytransition-metalalkali-metal
Standard Atomic Weight91.224 u223 u
Period57
Group41
Blockss
Phase at STPsolidsolid
Electron configuration[Kr]5s24d2[Rn]7s1
Oxidation states[1, 2, 3, 4][1]
Electronegativity (Pauling)1.330.7
Electron affinity0.426 eV0.491 eV
Density6520 kg/m³1870 kg/m³
Melting point1854.85 °C26.85 °C
Boiling point4408.85 °C-273.15 °C
Discovery year17891939