Gadolinium vs Meitnerium

PropertyGd GadoliniumMt Meitnerium
Atomic number64109
SymbolGdMt
NameGadoliniumMeitnerium
Categorylanthanidetransition-metal
Standard Atomic Weight157.25 u278 u
Period67
GroupN/A9
Blockss
Phase at STPsolidN/A
Electron configuration[Xe]6s24f75d1[Rn]7s25f146d7(calculated)
Oxidation states[0, 1, 2, 3][1, 3, 4, 6, 8, 9]
Electronegativity (Pauling)1.2N/A
Electron affinity0.132 eV1.7 eV
Density7900 kg/m³3.740000e+4 kg/m³
Melting point1312.85 °C-273.15 °C
Boiling point3272.85 °C-273.15 °C
Discovery year18861982