Plutonium vs Meitnerium

PropertyPu PlutoniumMt Meitnerium
Atomic number94109
SymbolPuMt
NamePlutoniumMeitnerium
Categoryactinidetransition-metal
Standard Atomic Weight244 u278 u
Period77
GroupN/A9
Blockss
Phase at STPsolidN/A
Electron configuration[Rn]7s25f6[Rn]7s25f146d7(calculated)
Oxidation states[2, 3, 4, 5, 6, 7, 8][1, 3, 4, 6, 8, 9]
Electronegativity (Pauling)1.28N/A
Electron affinity-0.5 eV1.7 eV
Density1.984000e+4 kg/m³3.740000e+4 kg/m³
Melting point639.85 °C-273.15 °C
Boiling point3227.85 °C-273.15 °C
Discovery year19411982