Sentence:  It would appear that it should be possible to determine unique mechanisms for the thermal and photochemical reactions in both the liquid and gas phases and to determine values for activation energies of some of the intermediate reactions of atoms and free radicals , as well as information on the heat of dissociation of the carbon <WSD>halogen</WSD> bond . 
Meaning of the word marked with <WSD> tags:  any of five related nonmetallic elements (fluorine or chlorine or bromine or iodine or astatine) that are all monovalent and readily form negative ions