Among the statements (I-IV) the correct ones areI) Be has smaller atomic radius compared to MgII) Be has higher ionization enthalpy than Al.III) Charge /radius ratio to Be is greater than that of Al.IV) Both Be and Al form mainly covalent compounds

I. The atomic radius of Be is smaller than that of Mg as we move downward in a group atomic size decreasesII. Ionization enthalpy of Be is more than that Alof  because Be is smaller than Al. Further from Be electron is removed from 2s which is nearer to nucleus. In  Al the eletron is removed from 3p which is away from the nucleusIII. Charge/radius ratio of Be is less than that  of  Al because Be carries 2+ charges and Al carries 3+ charges. But ionic radii of Be2+ and  Al3+are almost equal.IV. Because of more polarizing power compounds of Be and Al are covalent.