Which of the following is correct regarding chlorination of methane in the presence of sunlight

The mechanism involves a chain reaction. During a chain reaction, for every reactive species you start off with, a new one is generated at the end - and this keeps the process going. The over-all process is known as free radical substitution, or as a free radical chain reaction.

• Chain initiation: The chain is initiated (started) by UV light breaking a chlorine molecule into free radicals.
• ${\mathrm{Cl}}_2\stackrel{\mathrm{hv}}{\to }2{\mathrm{Cl}}^{\mathbf{·}}$
• Chain propagation reactions : These are the reactions which keep the chain going.
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• Chain termination reactions: These are reactions which remove free radicals from the system without replacing them by new ones.