Identify the incorrect statement from the following:

The largest and the smallest species among $\displaystyle \mathrm{Mg}, \mathrm{Mg}^{2+}, \mathrm{Al}$ and $\displaystyle \mathrm{Al}^{3+}$ are Al and $\displaystyle \mathrm{Mg}^{2+}$, respectively.

The IUPAC name of the element with atomic number $\displaystyle 107$ is Unnilseptium.

The similarity in behaviour of Li with Mg is referred to as 'diagonal relationship'.

The oxidation state and covalency of Al in $\displaystyle \left[\mathrm{AlCl}\left(\mathrm{H}_2 \mathrm{O}\right)_5\right]^{2+}$ are $\displaystyle 3$ and $\displaystyle 6$ respectively.