A crystalline solid of unknown origin forms an aqueous solution that conducts an electrical current. The solid has a high melting point and shatters when struck with a hammer. The solid is likely to be

This question appears incomplete

Explanation:

This question appears incomplete because of the absence of options. However, when a solid substance conducts electricity when dissolved in water (or in it's aqueous form) and has a high melting and boiling point, that substance is likely to be an electrovalent or ionic compound. This is because, ionic compounds are crystalline solids at room temperature with the properties above. Examples of ionic compounds are sodium chloride (NaCl) and potassium iodide (KI). The type of bond present in these compounds is what is referred to as the electrovalent/ionic bond.

it's c. elements are placed in rows based on how may valencies electrons have.