Answer:
1.![S^{-}(g)+e^{-} \rightarrow S^{2-}(g)](https://tex.z-dn.net/?f=S%5E%7B-%7D%28g%29%2Be%5E%7B-%7D%20%5Crightarrow%20S%5E%7B2-%7D%28g%29)
2.![Ti^{2+}(g) \rightarrow Ti^{3+}(g) \,\, IE = 2652.5\,kJ.mol^{-1}](https://tex.z-dn.net/?f=Ti%5E%7B2%2B%7D%28g%29%20%5Crightarrow%20Ti%5E%7B3%2B%7D%28g%29%20%5C%2C%5C%2C%20IE%20%3D%202652.5%5C%2CkJ.mol%5E%7B-1%7D)
3.The electron affinity of
is zero.
4.![O^{2-}(g) \rightarrow O^{-}(g)+e^{-}](https://tex.z-dn.net/?f=O%5E%7B2-%7D%28g%29%20%5Crightarrow%20O%5E%7B-%7D%28g%29%2Be%5E%7B-%7D)
Explanation:
1.
<u>Electron affinity:</u>
It is defined as the amount of energy change when an electron is added to atom in the gaseous phase.
The electron affinity of
is as follows.
![S^{-}(g)+e^{-} \rightarrow S^{2-}(g)](https://tex.z-dn.net/?f=S%5E%7B-%7D%28g%29%2Be%5E%7B-%7D%20%5Crightarrow%20S%5E%7B2-%7D%28g%29)
2.
<u>Ionization energy</u>:
Amount of energy required to removal of an electron from an isolated gaseous atom.
The third ionization energy of Titanium is as follows.
![Ti^{2+}(g) \rightarrow Ti^{3+}(g) \,\, IE = 2652.5\,kJ.mol^{-1}](https://tex.z-dn.net/?f=Ti%5E%7B2%2B%7D%28g%29%20%5Crightarrow%20Ti%5E%7B3%2B%7D%28g%29%20%5C%2C%5C%2C%20IE%20%3D%202652.5%5C%2CkJ.mol%5E%7B-1%7D)
3.
The electronic configuration of Mg: ![1s^{2}2s^{2}2p^{6}3s^{2}](https://tex.z-dn.net/?f=1s%5E%7B2%7D2s%5E%7B2%7D2p%5E%7B6%7D3s%5E%7B2%7D)
By the removal of two electrons from a magnesium element we get
ion.
has inert gas configuration i.e,![1s^{2}2s^{2}2p^{6}](https://tex.z-dn.net/?f=1s%5E%7B2%7D2s%5E%7B2%7D2p%5E%7B6%7D)
Hence, it does not require more electrons to get stability.
Therefore,the electron affinity of
is zero.
4.
The ionization energy of
is follows.
![O^{2-}(g) \rightarrow O^{-}(g)+e^{-}](https://tex.z-dn.net/?f=O%5E%7B2-%7D%28g%29%20%5Crightarrow%20O%5E%7B-%7D%28g%29%2Be%5E%7B-%7D)