Melting Dissolving Ionic Compounds with Water Solubility

The high melting points of ionic solids indicate that a lot of energy must be supplied to separate the ions from one another. How is it possible that the ions can separate from one another when soluble ionic compounds are dissolved in water, often with essentially no temperature change ... 

In which of the following states would NaCl be electrically conducting (a) solid, (b) molten (that is, melted), (c) dissolved in water. Explain your answers. Beryllium forms a compound with chlorine that has the empirical formula BeC. How would you determine whether it is an ionic compound (The compound is not soluble in water.)... 

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