Initiation Step:Formation of Chlorine Atom ga: ：+photon (hv)) A chlorine molecule splits homolytically into chlorine atoms (free radicals). 2013 Pearson Education,Inc. Chapter4 5© 2013 Pearson Education, Inc. Initiation Step: Formation of Chlorine Atom A chlorine molecule splits homolytically into chlorine atoms (free radicals). Chapter 4 5