Rutherfordium vs Meitnerium

PropertyRf RutherfordiumMt Meitnerium
Atomic number104109
SymbolRfMt
NameRutherfordiumMeitnerium
Categorytransition-metaltransition-metal
Standard Atomic Weight263 u278 u
Period77
Group49
Blockss
Phase at STPsolidN/A
Electron configuration[Rn]7s25f146d2[Rn]7s25f146d7(calculated)
Oxidation states[3, 4][1, 3, 4, 6, 8, 9]
Electronegativity (Pauling)N/AN/A
Electron affinity0.65 eV1.7 eV
Density2.330000e+4 kg/m³3.740000e+4 kg/m³
Melting point2126.85 °C-273.15 °C
Boiling point5526.85 °C-273.15 °C
Discovery year19641982