Water when irradiated with x-rays or γ-rays results into the formation of high energy electrons. These high energy electrons are known as Hydrated Electron.
During collisions these electrons lose some part of energy and are said to become thermalised. The electron which is thermalised get hydrated and forms intensely colored hydrated ion, e– (aq). This ion exhibits a wide absorption spectrum.
The electron which is hydrated is highly reactive and it easily gets reacted with water as well as with H+ ions.
e– (aq) + H2O——> H + OH–
e– (aq) + H+ ——> H
The hydrated electron acts as a reducing agent. For example:
Cu2+ + e– (aq)——> Cu+
[Cu2+ + H——> Cu+ + H+]
