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Why is copper a good conductor of heat?

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A periodic table element box for copper shows its symbol Cu, atomic number 29, atomic weight 63.546, electron configuration, and name. Icons indicate copper is a solid, weakly basic transition metal with face-centered cubic crystal structure. A key explains the symbols and color coding. — copper Properties of copper.

Copper is an exceptionally good conductor of heat due to its atomic structure, which is characteristic of metals. Like other metals, copper possesses non-localized, or "free," valence electrons that move throughout the solid crystal structure.12

Thermal conduction in solids occurs through the agitation of particles and the exchange of energy between adjacent molecules and these free electrons. Because copper has a high degree of atomic symmetry and a structure that facilitates the movement of these electrons, it allows for the efficient transfer of thermal energy across the material.3412

The effectiveness of this process is highly dependent on the purity of the copper. Impurities, such as those found in alloys, introduce irregularities into the crystal structure that scatter electrons and interfere with their movement, thereby reducing the metal's thermal conductivity.15