Because iodine is a liquid, it has no melting point. Iodine is not an electrical conductor because each molecule consists of two iodine atoms connected by a covalent bond that cannot be stimulated sufficiently to transmit electrical energy.
Because in an aqueous solution of iodine, iodine atoms are joined to each other by simple covalent bonds. Thus, when excitation occurs, the strength of the covalent bond is too weak to be able to transfer electrons, thus lacking the ability to conduct electricity.