Radical substitution on alcanes: Reaction of bromine on methane. Mechanism with equations

Initiation: $Br_2$ $ \begin{matrix} h\nu \\ \rightarrow \end{matrix} $ $2Br\cdot$ Propagation: $Br\cdot$ $ + $ $CH_4$ $\rightarrow$ $ CH_3\cdot$ $ +$ $ HBr$ $CH_3\cdot$ $ +$ $Br_2$ $ \rightarrow$ $ CH_3Br$ $+$ $ Br\cdot$

$Br_2$ $+$ $CH_4$ $\rightarrow$ $CH_3Br$ $+$ $HBr$