Cerium vs Protactinium

PropertyCe CeriumPa Protactinium
Atomic number5891
SymbolCePa
NameCeriumProtactinium
Categorylanthanideactinide
Standard Atomic Weight140.116 u231.03588 u
Period67
GroupN/AN/A
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f15d1[Rn]7s25f26d1
Oxidation states[1, 2, 3, 4][2, 3, 4, 5]
Electronegativity (Pauling)1.121.5
Electron affinity0.955 eV0.123 eV
Density6770 kg/m³1.537000e+4 kg/m³
Melting point797.85 °C1571.85 °C
Boiling point3423.85 °C-273.15 °C
Discovery year18011913