Hafnium vs Fermium

PropertyHf HafniumFm Fermium
Atomic number72100
SymbolHfFm
NameHafniumFermium
Categorytransition-metalactinide
Standard Atomic Weight178.49 u257 u
Period67
Group4N/A
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f145d2[Rn] 5f12 7s2
Oxidation states[-2, 0, 1, 2, 3, 4][2, 3]
Electronegativity (Pauling)1.31.3
Electron affinity0.178 eV0.339 eV
Density1.330000e+4 kg/m³9700 kg/m³
Melting point2232.85 °C1526.85 °C
Boiling point4602.85 °C-273.15 °C
Discovery year19111952