Curium vs Fermium

PropertyCm CuriumFm Fermium
Atomic number96100
SymbolCmFm
NameCuriumFermium
Categoryactinideactinide
Standard Atomic Weight247 u257 u
Period77
GroupN/AN/A
Blockss
Phase at STPsolidsolid
Electron configuration[Rn]7s25f76d1[Rn] 5f12 7s2
Oxidation states[3, 4, 5, 6][2, 3]
Electronegativity (Pauling)1.31.3
Electron affinity0.277 eV0.339 eV
Density1.351000e+4 kg/m³9700 kg/m³
Melting point1344.85 °C1526.85 °C
Boiling point3126.85 °C-273.15 °C
Discovery year19441952