Reactive species and atomic hydrogen:

Hydrated electrons might interact along with H₂O⁺ ions in solution or along with water molecules. Both reactions generate another reactive species and atomic hydrogen.

e^-_aq +   H₃O⁺   → H + H₂O                                                   (1)

or

e^-_aq +   H₂O → H +    OH^-                                                      (2)

Reaction (1) commonly predominates.

Since Reactions (1) and (2) are slow compared to which in Reaction (3), there are three reactive species present at any one time:  hydroxyl radicals (OH), hydrated electrons (e ^-), and hydrogen atoms (H). Those species might undergo any of various possible reactions like as the following.

OH + OH → H₂O₂ (hydrogen peroxide)                                      (3)

OH +H → H₂O                                                                             (4)

H +H → H₂                                                                                   (5)

H₂ + OH → H₂O +H                                                                       (6)

Hydrogen peroxide, established through Reaction (4), might also react along with the original reactive species, but at high temperatures H₂O₂ is unstable, and the predominant reaction is decomposition.

2H₂O₂ → O₂ + 2H₂O                                                                        (7)