A binding energy is required to decompose a bound system into its atoms.
Atoms form chemical bonds because they assume a lower energy level in bound state than in the atomic state. This is due to the fact that in bonding, valence electrons of one ligand can change to the other ligand’s free places which have a lower energy level. To release the bond, the necessary energy must be supplied to the ligands in order to bring them to the energy level in the unbound state. This bonding energy is expressed in the unit [kJ/mol]. Sufficient energy for the separation of molecular bonds can be supplied by strong heating or also by high-energy UV radiation. This UV radiation is generated in the plasma. The UV radiation in the plasma breaks up the molecule bonds, causing radicals to form.