When two or more elements combine with or without the application of heat, a compound is formed. Any compound in which the elements have a complete gain and loss of electron is termed as ionic compound.
Ionic compounds have the excellent property of dissolving in water. They form ions, both positively charged and negatively charged, which conduct electricity in aqueous medium and therefore can be called as electrolytes.
Sodium chloride (Table Salt) is a common example of ionic compound. It dissolves in water. It is an electrolyte and it is an excellent conductor of electricity. So, the best choice would be Sodium chloride.
