The oxide is ionic if there is charge transfer from one atom to another, i.e. when the electronegativity difference is large between O and the other element. This is the case for metals like Mg and Li. The oxide is molecular if the atoms share electrons equally, i.e. when the electronegativity difference is small between O and the other element. This is the case for the nonmetals like S, P, N and Xe. Solution The oxide is ionic if there is charge transfer from one atom to another, i.e. when the electronegativity difference is large between O and the other element. This is the case for metals like Mg and Li. The oxide is molecular if the atoms share electrons equally, i.e. when the electronegativity difference is small between O and the other element. This is the case for the nonmetals like S, P, N and Xe..