A termination step is a step in a chain reaction in which two radicals combine with each other, so that they are removed from the system and the chain comes to an end. Because radicals are consumed without any being produced, termination reduces the number of chain carriers. It is the step that finally stops a chain reaction.

链终止步骤是链反应中的一步,其中两个自由基彼此结合,因而从体系中被消除,链反应也随之结束。由于自由基被消耗而没有任何新的产生,链终止减少了链载体的数目。它是最终使链反应停止的步骤。