The halon bromochlorodifluoromethane (CF2ClBr\text{CF}_2\text{ClBr}CF2ClBr), once widely used in aviation fire-suppression systems, can migrate to the stratosphere where it undergoes photolysis by absorbing ultraviolet radiation, contributing to ozone depletion.
Which equation represents the initiation step that occurs when a molecule of CF2ClBr\text{CF}_2\text{ClBr}CF2ClBr absorbs ultraviolet radiation?
CF2ClBr→∙CF2Br+∙Cl\text{CF}_2\text{ClBr} \rightarrow \bullet\text{CF}_2\text{Br} + \bullet\text{Cl}CF2ClBr→∙CF2Br+∙Cl
CF2ClBr→∙CF2Cl+∙Br\text{CF}_2\text{ClBr} \rightarrow \bullet\text{CF}_2\text{Cl} + \bullet\text{Br}CF2ClBr→∙CF2Cl+∙Br
CF2ClBr→∙CFClBr+∙F\text{CF}_2\text{ClBr} \rightarrow \bullet\text{CFClBr} + \bullet\text{F}CF2ClBr→∙CFClBr+∙F
CF2ClBr→CF2Cl++Br−\text{CF}_2\text{ClBr} \rightarrow \text{CF}_2\text{Cl}^+ + \text{Br}^-CF2ClBr→CF2Cl++Br−
