Gadolinium vs Thulium

PropertyGd GadoliniumTm Thulium
Atomic number6469
SymbolGdTm
NameGadoliniumThulium
Categorylanthanidelanthanide
Standard Atomic Weight157.25 u168.93422 u
Period66
GroupN/AN/A
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f75d1[Xe]6s24f13
Oxidation states[0, 1, 2, 3][0, 1, 2, 3]
Electronegativity (Pauling)1.21.25
Electron affinity0.132 eV1.029 eV
Density7900 kg/m³9320 kg/m³
Melting point1312.85 °C1544.85 °C
Boiling point3272.85 °C1949.85 °C
Discovery year18861879