Consider the following equation: $$\mathrm{Ca}^{+}(g)+\mathrm{e}^{-} \longrightarrow \mathrm{Ca}(g)$$ Which of the following statements are true? (i) The energy change for this process is the electron affinity of the Ca' ion. (ii) The energy change for this process is the negative of the first ionization energy of the Ca atom. (ii) The energy change for this process is the negative of the electron affinity of the Ca atom.

: Statement (i) says that the energy change for this process is the electron affinity of the Ca+ ion. Electron affinity refers to the change in energy when an electron is added to a neutral atom to form a negatively charged ion. In this case, an electron is being added to a Ca+ ion. Therefore, we need to analyze whether the energy change corresponds to the electron affinity.

: Statement (ii) states that the energy change for this process is the negative of the first ionization energy of the Ca atom. Ionization energy refers to the energy required to remove an electron from an atom or ion. The first ionization energy specifically refers to the energy required to remove the first electron from the neutral atom. In this case, since an electron is being added to the positive Ca+ ion, we should analyze whether the energy change is equal to the negative of the first ionization energy of the Ca atom.

: Statement (iii) says that the energy change for this process is the negative of the electron affinity of the Ca atom. As we have mentioned before, electron affinity refers to the change in energy when an electron is added to a neutral atom to form a negatively charged ion. Here, an electron is being added to a Ca+ ion; therefore, we need to analyze if the energy change is equal to the negative of the electron affinity of the Ca atom.

: Statement (i) is incorrect because the energy change is not related to the electron affinity of the Ca+ ion, since electron affinity refers specifically to the addition of an electron to a neutral atom, not to a charged ion like Ca+. Statement (ii) is correct because the energy change can be considered the negative of the first ionization energy of the Ca atom. This is because ionization energy is the energy required to remove an electron (form a positive ion), while in our case an electron is being added (forming a neutral atom). Therefore, the energy change is the opposite of the ionization energy. Statement (iii) is incorrect because the energy change is not related to the electron affinity of the Ca atom. While the process involves the addition of an electron, it is not being added to a neutral Ca atom, but rather to a Ca+ ion.