1. Unique properties of hydrogen -- 2. Hydrogen bond -- 3. Hydrogen in nuclear fusion -- 4. Photosynthesis -- 5. Hydrogen in metabolism : oxidative respiration -- 6. Biohydrogen production -- 7. Hydrogen production via water splitting under the action of light -- 8. Conventional methods of hydrogen production -- 9. Hydrogen fuel cells -- 10. Hydrogen storage -- 11. Production of atomic photochemical hydrogen and photoinjection of hydrogen in solids.