Breaking the bonds in one mole of hydrogen molecules requires about:

1. In hydrogen the single electrons on each atom interact with both nuclei, occupying the space around both atoms. 2. That shared arrangement is a very strong covalent bond. 3. A large amount of energy, 436 kilojoules, must be added to break the bonds in one mole of hydrogen molecules and cause the atoms to separate. 4. The same figure is released when those bonds form. _Source: OpenStax Chemistry 2e (CC BY 4.0), Ch 7 'Chemical Bonding and Molecular Geometry', sections 7.1-7.6_