Thorium vs Californium

PropertyTh ThoriumCf Californium
Atomic number9098
SymbolThCf
NameThoriumCalifornium
Categoryactinideactinide
Standard Atomic Weight232.0377 u251 u
Period77
GroupN/AN/A
Blockss
Phase at STPsolidsolid
Electron configuration[Rn]7s26d2[Rn]7s25f10
Oxidation states[-1, 1, 2, 3, 4][2, 3, 4, 5]
Electronegativity (Pauling)1.31.3
Electron affinity0.607 eV-0.5 eV
Density1.172000e+4 kg/m³1.510000e+4 kg/m³
Melting point1749.85 °C899.85 °C
Boiling point4787.85 °C-273.15 °C
Discovery year18281950