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