i)Magnesium and Beryllium are group II elements, and form ions with a charge of +2. The electronic configuration of Mg+2 ion is: 1s^2 2s^2 2p^6 ii)It is easier for magnesium to form a cation than beryllium as beryllium has really high electronegativity and ionization energy due to: Small Atomic radius Lesser shielding effect (only 1 intervalence shell)