Why will plastic tubing and an iron rod conduct electricity?

Plastic tubing does not conduct electricity because it is an insulator, preventing the flow of electric current. In contrast, an iron rod conducts electricity because it is a metal, allowing free movement of electrons throughout its structure. Metals like iron have a high density of free electrons, which facilitate electrical conductivity, while plastics lack these free-moving charge carriers. Therefore, only the iron rod will effectively conduct electricity.