A radical reaction refers to a process in which molecules undergo a chemical reaction by breaking and forming bonds through the formation of free radicals. There are a handful of synonyms that can be used to describe this type of reaction, including chain reaction, homolytic reaction, and free radical reaction. These terms are used interchangeably to refer to the same type of reaction that occurs when atoms or molecules react chemically and release energy in the form of heat or light. Whether you call it a radical reaction, a homolytic reaction, or a free radical reaction, they all describe a critical process necessary in the study of chemistry.