The formation of an ionic bond involves the what?

Answer is: transfer of electrons.
Ionic bond is the electrostatic attraction between oppositely charged ions.
For example, compound magnesium chloride (MgCl₂) has ionic bond.
Magnesium (Mg) transfers two electrons, became positive cation, to chlorine (Cl), which became negative anion.
Magnesium is metal from group 2 and chlorine is nonmetal from group 17 of the Periodic table.

You know how the first one if filled up like the objects do the same but with the other categories