Hydrogen vs Beryllium

PropertyH HydrogenBe Beryllium
Atomic number14
SymbolHBe
NameHydrogenBeryllium
Categorynonmetalalkaline-earth-metal
Standard Atomic Weight1.007975 u9.012183 u
Period12
Group12
Blockss
Phase at STPgassolid
Electron configuration1s1[He]2s2
Oxidation states[-1, 1][0, 1, 2]
Electronegativity (Pauling)2.21.57
Electron affinity0.75419 eV-0.52 eV
Density0.08988 kg/m³1850 kg/m³
Melting point-259.34 °C1286.85 °C
Boiling point-252.87 °C2470.85 °C
Discovery year17661797