What is a material that does not allow electric charges to flow easily called?

A material that does not allow electric charges to flow easily is referred to as an insulator. Insulators have tightly bound electrons, which restrict their movement under an electric field. This property minimizes the flow of electric current, making insulators essential for containing and directing electrical energy safely, as seen in materials like rubber, glass, and plastic.

In contrast, conductors facilitate the flow of electric charges with minimal resistance due to their free-moving electrons. Superconductors represent a specialized category that allows electric current to flow without resistance under specific conditions, but they are not the general term for materials that impede charge flow. Resistors, on the other hand, are designed to limit current flow in a circuit but are made from materials that do allow some level of current to pass through. Thus, among the options provided, the term that best describes a material with poor conductivity is clearly an insulator.