What term describes materials that are not good conductors of electricity?

The term that describes materials that are not good conductors of electricity is insulators. Insulators are substances that resist the flow of electric current, meaning they do not easily allow electrons to move through them. This ability makes insulators important in many electrical applications, as they help protect against unwanted current flow, ensuring safety and efficiency in circuits.

In contrast, conductors are materials that permit the flow of electricity, like metals such as copper and aluminum, which have free electrons that move easily. Superconductors are a special class of conductors that exhibit zero electrical resistance under certain conditions, typically at very low temperatures. Semiconductors have properties that are between conductors and insulators; they can conduct electricity under some conditions and insulate it under others, making them invaluable in electronic devices but not applicable in the context of materials that are poor conductors overall.