What happens during the propagation step of radical substitution?

During the propagation step of radical substitution, the primary process involves the formation of products while simultaneously generating new radicals. This step is crucial in the radical substitution mechanism, as it allows the reaction to continue by enabling the radicals to react with available reactants, thereby producing new radicals in the process.

In a typical radical substitution reaction, such as the chlorination of alkanes, a radical (for instance, a chlorine radical) will abstract a hydrogen atom from the alkane, resulting in the formation of a new molecule (a haloalkane) and generating a new radical (another chlorine radical). This new radical can then initiate further propagation steps, effectively extending the reaction.

The generation of new radicals while forming products illustrates the chain reaction characteristic of radical substitution. This continuous cycle is what allows the reaction to proceed until the reactants are nearly depleted or until termination steps, which are not part of the propagation stage, occur.

Other options fail to accurately describe the fundamental characteristics of the propagation stage. For instance, the formation of radicals decreasing in concentration doesn't align with the continuous generation of new radicals during propagation, while the idea that all radicals are consumed is incorrect, as it contradicts the ongoing chain reaction. Additionally, the notion that only one product is formed