Gadolinium vs Mendelevium

PropertyGd GadoliniumMd Mendelevium
Atomic number64101
SymbolGdMd
NameGadoliniumMendelevium
Categorylanthanideactinide
Standard Atomic Weight157.25 u258 u
Period67
GroupN/AN/A
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f75d1[Rn]7s25f13
Oxidation states[0, 1, 2, 3][2, 3]
Electronegativity (Pauling)1.21.3
Electron affinity0.132 eV0.997 eV
Density7900 kg/m³1.030000e+4 kg/m³
Melting point1312.85 °C826.85 °C
Boiling point3272.85 °C-273.15 °C
Discovery year18861955