Which equation shows an energy change equal to the first ionisation energy of bromine?
- A$\mathrm{Br}(g) \rightarrow \mathrm{Br}^{+}(g) + e^{-}$
- B$\mathrm{Br}(g) \rightarrow \mathrm{Br}^{-}(g) - e^{-}$
- C$\frac{1}{2}\mathrm{Br}_2(g) \rightarrow \mathrm{Br}^{+}(g) + e^{-}$
- D$\frac{1}{2}\mathrm{Br}_2(g) \rightarrow \mathrm{Br}^{-}(g) - e^{-}$