Zirconium vs Mendelevium

PropertyZr ZirconiumMd Mendelevium
Atomic number40101
SymbolZrMd
NameZirconiumMendelevium
Categorytransition-metalactinide
Standard Atomic Weight91.224 u258 u
Period57
Group4N/A
Blockss
Phase at STPsolidsolid
Electron configuration[Kr]5s24d2[Rn]7s25f13
Oxidation states[1, 2, 3, 4][2, 3]
Electronegativity (Pauling)1.331.3
Electron affinity0.426 eV0.997 eV
Density6520 kg/m³1.030000e+4 kg/m³
Melting point1854.85 °C826.85 °C
Boiling point4408.85 °C-273.15 °C
Discovery year17891955