Which materials are considered good conductors of heat?

Metals are considered good conductors of heat due to their atomic structure. In metals, there are free electrons that move easily throughout the material. When heat is applied to one part of a metal, these free electrons gain energy and move rapidly, transferring the heat efficiently throughout the metal.

This property of thermal conductivity is particularly strong in metals such as copper and aluminum, which are often used for wires and cookware because they allow heat to pass through them quickly. In contrast, gases, plastics, and wood are generally poor conductors of heat. Gases have particles that are far apart, which limits the transfer of heat via particle collisions. Plastics and wood are composed of non-metallic compounds that do not have free electrons, resulting in low thermal conductivity, making them useful as insulators.