Zirconium vs Rutherfordium

PropertyZr ZirconiumRf Rutherfordium
Atomic number40104
SymbolZrRf
NameZirconiumRutherfordium
Categorytransition-metaltransition-metal
Standard Atomic Weight91.224 u263 u
Period57
Group44
Blockss
Phase at STPsolidsolid
Electron configuration[Kr]5s24d2[Rn]7s25f146d2
Oxidation states[1, 2, 3, 4][3, 4]
Electronegativity (Pauling)1.33N/A
Electron affinity0.426 eV0.65 eV
Density6520 kg/m³2.330000e+4 kg/m³
Melting point1854.85 °C2126.85 °C
Boiling point4408.85 °C5526.85 °C
Discovery year17891964