Zirconium vs Americium

PropertyZr ZirconiumAm Americium
Atomic number4095
SymbolZrAm
NameZirconiumAmericium
Categorytransition-metalactinide
Standard Atomic Weight91.224 u243 u
Period57
Group4N/A
Blockss
Phase at STPsolidsolid
Electron configuration[Kr]5s24d2[Rn]7s25f7
Oxidation states[1, 2, 3, 4][2, 3, 4, 5, 6, 7]
Electronegativity (Pauling)1.331.3
Electron affinity0.426 eV0.1 eV
Density6520 kg/m³1.369000e+4 kg/m³
Melting point1854.85 °C1175.85 °C
Boiling point4408.85 °C2010.85 °C
Discovery year17891944