A material that does NOT allow the flow of electrons is known as what?

A material that does not allow the flow of electrons is identified as an insulator. Insulators are characterized by their high resistance to electrical current, meaning they do not permit electrons to move through them easily. This property is crucial in various applications, such as electrical wiring, where it is important to prevent unintended flow of electricity that could lead to short circuits or other hazards.

In contrast, conductors allow the free flow of electrons, making them essential for electrical circuits. Resistors are components designed to limit current flow in a circuit, often using materials that may behave as insulators at different levels. Semiconductors have properties between conductors and insulators and can conduct electricity under specific conditions, such as the introduction of impurities or changes in temperature, making them integral to modern electronics.

Understanding these distinctions clarifies the role and functionality of different materials in electrical engineering and technology.