Explanation:
Atomic number of magnesium is 12 and its electronic distribution is 2, 8, 2. On the other hand, atomic number of iodine is 53 and its electronic configuration is [tex][Kr]4d^{10}5s^{2}5p^{5}[/tex].
Hence, there are 7 valence electrons in an iodine atom and there are 2 valence electrons in a magnesium atom.
So, one atom of iodine requires one electron from a donor atom to complete its octet. But one magnesium atom contains two valence electrons.
Therefore, one magnesium atom will combine with two iodine atoms to result in the formation of magnesium iodide as follows.
[tex]Mg^{2+} + 2I^{-} \rightarrow MgI_{2}[/tex]
Therefore, an ionic bond will be formed when magnesium reacts with iodine to make magnesium iodide.
