# Chemistry question. Which of the following statements are true?

## $C {a}^{+} \left(g\right)$ + ${e}^{-}$ $\to C a$(g) i.) The energy change for this process is the negative of the first ionization energy of the $C {a}^{+}$ ion. ii). The energy change for this process is the negative of the first ionization energy of the Ca atom. iii). The energy change for this process is the negative of the electron affinity of the Ca atom.

##### 1 Answer
Nov 19, 2017

The third answer is true.

#### Explanation:

The first two statements reference the ionization energy, which is the energy required to REMOVE an electron.

On the other hand, electron affinity is the energy either released/absorbed when an atom GAINS an electron.

We can see from the chemical equation that an electron is being added, thus it is the electron affinity.