Ahard, crystalline solid with a high melting point does not conduct electricity in any phase. this solid is most likely:
(a) an ionic solid.
(b) a metallic solid.
(c) a molecular solid.
(d) a network covalent solid.

The answer to your question is letter C

Explanation:

(A) an ionic solid.    These compounds can conduct electricity in solution so this answer is incorrect.

(B) a metallic solid.  A metallic compound can conduct electricity in a solid state, this answer is incorrect.

(C) a molecular solid.  These compounds have low melting points, low electrical conductivity, etc, so this is the correct answer.

(D) a network covalent solid. These compounds have similar properties to ionic compounds like high melting points. So this answer is incorrect.

the dissolution of polymer can be thermodynamically described in 2 steps.