Ytterbium vs Fermium

PropertyYb YtterbiumFm Fermium
Atomic number70100
SymbolYbFm
NameYtterbiumFermium
Categorylanthanideactinide
Standard Atomic Weight173.054 u257 u
Period67
GroupN/AN/A
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f14[Rn] 5f12 7s2
Oxidation states[0, 1, 2, 3][2, 3]
Electronegativity (Pauling)N/A1.3
Electron affinity-0.02 eV0.339 eV
Density6900 kg/m³9700 kg/m³
Melting point818.85 °C1526.85 °C
Boiling point1195.85 °C-273.15 °C
Discovery year18781952