Boron vs Meitnerium

PropertyB BoronMt Meitnerium
Atomic number5109
SymbolBMt
NameBoronMeitnerium
Categorymetalloidtransition-metal
Standard Atomic Weight10.8135 u278 u
Period27
Group139
Blockps
Phase at STPsolidN/A
Electron configuration[He]2s22p1[Rn]7s25f146d7(calculated)
Oxidation states[-5, -1, 0, 1, 2, 3][1, 3, 4, 6, 8, 9]
Electronegativity (Pauling)2.04N/A
Electron affinity0.27972 eV1.7 eV
Density2370 kg/m³3.740000e+4 kg/m³
Melting point2074.85 °C-273.15 °C
Boiling point3999.85 °C-273.15 °C
Discovery year18081982