Samarium vs Fermium

PropertySm SamariumFm Fermium
Atomic number62100
SymbolSmFm
NameSamariumFermium
Categorylanthanideactinide
Standard Atomic Weight150.36 u257 u
Period67
GroupN/AN/A
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f6[Rn] 5f12 7s2
Oxidation states[0, 1, 2, 3][2, 3]
Electronegativity (Pauling)1.171.3
Electron affinity0.156 eV0.339 eV
Density7520 kg/m³9700 kg/m³
Melting point1073.85 °C1526.85 °C
Boiling point1793.85 °C-273.15 °C
Discovery year18781952