Ytterbium vs Protactinium

PropertyYb YtterbiumPa Protactinium
Atomic number7091
SymbolYbPa
NameYtterbiumProtactinium
Categorylanthanideactinide
Standard Atomic Weight173.054 u231.03588 u
Period67
GroupN/AN/A
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f14[Rn]7s25f26d1
Oxidation states[0, 1, 2, 3][2, 3, 4, 5]
Electronegativity (Pauling)N/A1.5
Electron affinity-0.02 eV0.123 eV
Density6900 kg/m³1.537000e+4 kg/m³
Melting point818.85 °C1571.85 °C
Boiling point1195.85 °C-273.15 °C
Discovery year18781913