Iridium vs Meitnerium

PropertyIr IridiumMt Meitnerium
Atomic number77109
SymbolIrMt
NameIridiumMeitnerium
Categorytransition-metaltransition-metal
Standard Atomic Weight192.217 u278 u
Period67
Group99
Blockss
Phase at STPsolidN/A
Electron configuration[Xe]6s24f145d7[Rn]7s25f146d7(calculated)
Oxidation states[-3, -2, -1, 1, 2, 3, 4, 5, 6, 7, 8, 9][1, 3, 4, 6, 8, 9]
Electronegativity (Pauling)2.2N/A
Electron affinity1.565 eV1.7 eV
Density2.256220e+4 kg/m³3.740000e+4 kg/m³
Melting point2445.85 °C-273.15 °C
Boiling point4427.85 °C-273.15 °C
Discovery year18031982