Thulium vs Californium

PropertyTm ThuliumCf Californium
Atomic number6998
SymbolTmCf
NameThuliumCalifornium
Categorylanthanideactinide
Standard Atomic Weight168.93422 u251 u
Period67
GroupN/AN/A
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f13[Rn]7s25f10
Oxidation states[0, 1, 2, 3][2, 3, 4, 5]
Electronegativity (Pauling)1.251.3
Electron affinity1.029 eV-0.5 eV
Density9320 kg/m³1.510000e+4 kg/m³
Melting point1544.85 °C899.85 °C
Boiling point1949.85 °C-273.15 °C
Discovery year18791950