Radical reactions involve the participation of free radicals, which are highly reactive molecules with unpaired electrons. These reactions are crucial in various chemical processes, including combustion, polymerization, and biological systems. Free radicals can initiate chain reactions, leading to the formation of new compounds. In organic chemistry, radical reactions often occur through mechanisms like initiation, propagation, and termination. Common examples include the halogenation of alkanes and the addition of radicals to alkenes. Understanding these reactions is essential for fields such as materials science and pharmaceutical development, where controlling radical behavior can lead to desired outcomes.