tu
Br2—hν→Br·+Br·CH3CH3+Br·—→CH3CH2·+HBr CH3CH2·+Br2—→CH3CH2Br+Br·CH3CH2·+Br·—→CH3CH2Br Br·+Br·—→Br2 CH3CH2·+CH3CH2·—→CH3CH2CH2CH3tu
Br2—hν→Br·+Br·CH3CH3+Br·—→CH3CH2·+HBr CH3CH2·+Br2—→CH3CH2Br+Br·CH3CH2·+Br·—→CH3CH2Br Br·+Br·—→Br2 CH3CH2·+CH3CH2·—→CH3CH2CH2CH3