dihydrogenH₂100%dihydrogen, dihydrogen, hydrogenElemental hydrogen.Space reserved for adsPhysical characteristicsMolecular mass 2.02Density 0.0899 g/m³Melting point -434 ℉-259 ℃14 K Boiling point -423 ℉-253 ℃20.3 K Synthesis of dihydrogensodium hydride + water → sodium hydroxide + dihydrogenCompound added to the database on October 27, 2020, last modified on August 5, 2022.