Chloromethane (CH3Cl\text{CH}_3\text{Cl}CH3Cl) can undergo further reaction with chlorine in the presence of ultraviolet radiation to form dichloromethane (CH2Cl2\text{CH}_2\text{Cl}_2CH2Cl2).
Which equation represents a propagation step in the mechanism for this reaction?
CH3Cl+Cl∙→CH2Cl2+H∙\text{CH}_3\text{Cl} + \text{Cl}^\bullet \rightarrow \text{CH}_2\text{Cl}_2 + \text{H}^\bulletCH3Cl+Cl∙→CH2Cl2+H∙
CH2Cl∙+Cl∙→CH2Cl2\text{CH}_2\text{Cl}^\bullet + \text{Cl}^\bullet \rightarrow \text{CH}_2\text{Cl}_2CH2Cl∙+Cl∙→CH2Cl2
CH2Cl∙+Cl2→CH2Cl2+Cl∙\text{CH}_2\text{Cl}^\bullet + \text{Cl}_2 \rightarrow \text{CH}_2\text{Cl}_2 + \text{Cl}^\bulletCH2Cl∙+Cl2→CH2Cl2+Cl∙
CH3Cl+Cl2→CH2Cl2+HCl\text{CH}_3\text{Cl} + \text{Cl}_2 \rightarrow \text{CH}_2\text{Cl}_2 + \text{HCl}CH3Cl+Cl2→CH2Cl2+HCl