Hydrogen vs Rubidium

PropertyH HydrogenRb Rubidium
Atomic number137
SymbolHRb
NameHydrogenRubidium
Categorynonmetalalkali-metal
Standard Atomic Weight1.007975 u85.4678 u
Period15
Group11
Blockss
Phase at STPgassolid
Electron configuration1s1[Kr]5s1
Oxidation states[-1, 1][-1, 1]
Electronegativity (Pauling)2.20.82
Electron affinity0.75419 eV0.4859 eV
Density0.08988 kg/m³1530 kg/m³
Melting point-259.34 °C39.31 °C
Boiling point-252.87 °C687.85 °C
Discovery year17661861