For calcium, the second ionisation energy is $1150\,\text{kJ mol}^{-1}$. Which equation shows this statement correctly?
- A$\text{Ca}(g) \rightarrow \text{Ca}^{2+}(g) + 2e^{-} ;\ \Delta H^{\circ} = +1150\,\text{kJ mol}^{-1}$
- B$\text{Ca}^+(g) \rightarrow \text{Ca}^{2+}(g) + e^{-} ;\ \Delta H^{\circ} = +1150\,\text{kJ mol}^{-1}$
- C$\text{Ca}(g) \rightarrow \text{Ca}^{2+}(g) + e^{-} ;\ \Delta H^{\circ} = -1150\,\text{kJ mol}^{-1}$
- D$\text{Ca}(g) \rightarrow \text{Ca}^{2+}(g) + 2e^{-} ;\ \Delta H^{\circ} = -1150\,\text{kJ mol}^{-1}$