Erbium vs Californium

PropertyEr ErbiumCf Californium
Atomic number6898
SymbolErCf
NameErbiumCalifornium
Categorylanthanideactinide
Standard Atomic Weight167.259 u251 u
Period67
GroupN/AN/A
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f12[Rn]7s25f10
Oxidation states[0, 1, 2, 3][2, 3, 4, 5]
Electronegativity (Pauling)1.241.3
Electron affinity0.312 eV-0.5 eV
Density9070 kg/m³1.510000e+4 kg/m³
Melting point1528.85 °C899.85 °C
Boiling point2867.85 °C-273.15 °C
Discovery year18431950