Each of the following proposed mechanisms for the free-radical chlorination of methane is wrong. Explain how the

Question:

Each of the following proposed mechanisms for the free-radical chlorination of methane is wrong. Explain how the experimental evidence disproves each mechanism.
(a) Cl2 + hv → Cl2* (an activated form of Cl2)
Cl2* + CH4 → HCl + CH3Cl
(b) CH4 + hv → ∙CH3 + H∙
∙CH3 + Cl2 → CH3 Cl + Cl∙
Cl∙ + H∙ → HCl