Which property is best to use when determining the strength of an ionic bond in a solid

Lattice energy

Conductivity

Hardness

Solubility

Lattice Energy

Lattice energy.

Explanation:

Ionic compounds are formed by the transfer of electrons from he electropositive element to the electronegative element. The ionic compounds conduct electricity in liquid state only.

The strength of the ionic solid can be determined by the lattice energy. Lattice energy may be defined as the energy released in the formation of ionic compounds. Larger the lattice energy of the ionic solids, the larger is the strength of the ionic solids. More force is required to break the ionic compoun that has high lattice energy.

Thus, the correct answer is option (a).