An insulator is defined as what type of material?

The definition of an insulator aligns with the description of a material that prevents or reduces the passage of heat, electricity, or sound. Insulators are essential in various applications, from building construction, where they help maintain temperature by reducing heat transfer, to electrical wiring, where they keep electrical currents contained and prevent shocks.

This property of insulators is crucial for their effectiveness in creating energy-efficient environments and ensuring safety in electrical systems. In contrast, the other options describe materials that either facilitate the flow of heat or electricity, or that are effective in conducting sound, which do not align with the characteristics of an insulating material. Thus, the understanding of insulators as materials that inhibit rather than promote the transfer of these forms of energy is foundational in both physical science and practical applications.