Page 117 - Radiation Safety
P. 117
Initial Physical Stage (~10 -16 s)
Energy is deposited to the cell and ionisation occurs.
+
H O ------------> H O + e -
2
2
-6
Physico-chemical Stage : (~10 s)
The free ions interact with other water molecules resulting in a number of new
products.
+
H O + -------------> H + OHº
2
H O + e - -------------> H O -
2
2
H O - --------------> Hº + OH -
2
Hº and OHº are called free radicals and are highly reactive.
OH + OH -------------------------> H O (Hydrogen Peroxide)
2 2
Radicals refers to an atom or molecule that contains an unpaired electron.
Radicals are highly reactive.
Radicals can be neutral or charged.
