Erbium vs Meitnerium

PropertyEr ErbiumMt Meitnerium
Atomic number68109
SymbolErMt
NameErbiumMeitnerium
Categorylanthanidetransition-metal
Standard Atomic Weight167.259 u278 u
Period67
GroupN/A9
Blockss
Phase at STPsolidN/A
Electron configuration[Xe]6s24f12[Rn]7s25f146d7(calculated)
Oxidation states[0, 1, 2, 3][1, 3, 4, 6, 8, 9]
Electronegativity (Pauling)1.24N/A
Electron affinity0.312 eV1.7 eV
Density9070 kg/m³3.740000e+4 kg/m³
Melting point1528.85 °C-273.15 °C
Boiling point2867.85 °C-273.15 °C
Discovery year18431982