Zirconium vs Californium

PropertyZr ZirconiumCf Californium
Atomic number4098
SymbolZrCf
NameZirconiumCalifornium
Categorytransition-metalactinide
Standard Atomic Weight91.224 u251 u
Period57
Group4N/A
Blockss
Phase at STPsolidsolid
Electron configuration[Kr]5s24d2[Rn]7s25f10
Oxidation states[1, 2, 3, 4][2, 3, 4, 5]
Electronegativity (Pauling)1.331.3
Electron affinity0.426 eV-0.5 eV
Density6520 kg/m³1.510000e+4 kg/m³
Melting point1854.85 °C899.85 °C
Boiling point4408.85 °C-273.15 °C
Discovery year17891950