The document summarizes the chemical reaction of chlorination of alkanes. It describes the reaction as a chain reaction, where (1) chlorine radicals are produced from chlorine molecules through homolytic fission initiated by heat or light. (2) The chlorine radicals react with methane to form methyl radicals and HCl molecules. (3) The methyl radicals react with chlorine molecules to form methyl chloride and new chlorine radicals. This sequence propagates the chain reaction until (4)-(6) termination steps form stable products and end the reaction.