Hydrogen vs Mendelevium

PropertyH HydrogenMd Mendelevium
Atomic number1101
SymbolHMd
NameHydrogenMendelevium
Categorynonmetalactinide
Standard Atomic Weight1.007975 u258 u
Period17
Group1N/A
Blockss
Phase at STPgassolid
Electron configuration1s1[Rn]7s25f13
Oxidation states[-1, 1][2, 3]
Electronegativity (Pauling)2.21.3
Electron affinity0.75419 eV0.997 eV
Density0.08988 kg/m³1.030000e+4 kg/m³
Melting point-259.34 °C826.85 °C
Boiling point-252.87 °C-273.15 °C
Discovery year17661955