Answer:
D
Explanation:
Sodium Chloride which is also know as common salt is formed by electrovalent bonding which is the combination Na cation and Cl anion. It forms a cubic crystal shape in its lattice. Because electrovalent bonds are strong NaCl are hard, and has high melting point as a high amount of energy would be required to break such bonds. NaCl however is a poor conductor of electricity in its crystalline form. But when in contact with moisture or in a molten form the conducting ions become free and it becomes a good conductor of electricity. But in our case study we are dealing with a crystal of NaCl hence its a poor conductor of electricity.
