Lattice energy of an ionic compound depends upon

Elements $X$ and $Y$ have $2$ and $6$ electrons in their valence shells,respectively. If they combine,what will be the possible formula of the compound formed?

When sodium and chlorine react,then:

An ionizing solvent has

Anhydrous $AlCl_3$ is covalent; however,when it is dissolved in water,hydrated ionic species are formed. This transformation is owing to

Ionic bonds are usually formed by the combination of elements with: