Answer:
See explanation
Step-by-step explanation:
In the image attached, I have shown the mechanism for the free radical chlorination of chloromethane to give dichloromethane.
The initiation step is the homolytic fission of the chlorine molecule to yield two chlorine radicals which proceed to the propagation steps.
In the propagation steps, one chlorine radical produced during the initiation step attacks chloromethane to yield a chloromethane radical. This radical attacks with a chlorine molecule yielding the dichloromethane and producing another chlorine radical to continue the propagation steps.
The half arrows in the image signify a transfer of only one electron.