Terbium vs Thulium

PropertyTb TerbiumTm Thulium
Atomic number6569
SymbolTbTm
NameTerbiumThulium
Categorylanthanidelanthanide
Standard Atomic Weight158.92535 u168.93422 u
Period66
GroupN/AN/A
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f9[Xe]6s24f13
Oxidation states[0, 1, 2, 3, 4][0, 1, 2, 3]
Electronegativity (Pauling)N/A1.25
Electron affinity1.124 eV1.029 eV
Density8230 kg/m³9320 kg/m³
Melting point1355.85 °C1544.85 °C
Boiling point3229.85 °C1949.85 °C
Discovery year18431879