Hydrogen

engl. hydrogen entlehnt von frz. hydrogène (“hydrogen”),
- gebildet durch den frz. Chemiker Louis-Bernard Guyton de Morveau (1737–1816) und Antoine Lavoisier (1743–1794)
  - aus agr. hydro- ‘Wasser’ + -gèn (suffixdenoting a producer of something),
  - von der Tatsache her, daß Wasser als Verbindung entsteht, wenn Hydrogen oxidiert.

The prefix hydro- is borrowed from Ancient Greek ῠ̔δρο- (hŭdro-), from ῡ̆̔́δωρ (hū̆́dōr, “water”), ultimately from Proto-Indo-European *wed- (“water”).
The suffix -gène is borrowed from Ancient Greek -γενής (-genḗs, suffix meaning ‘born in a certain condition or place’), from γένος (génos, “descendant, offspring; race; etc.”) (ultimately from Proto-Indo-European*ǵenh₁- (“to beget, produce; to give birth”)) + -ης (-ēs, suffix forming some third-declension adjectives).

By surface analysis, hydro- (prefix meaning ‘water’) +‎ -gen (suffix denoting a producer of something).