The capability of a metal to conduct heat is defined as the metal's thermal conductivity. This property varies by metal type and is crucial to consider in applications that frequently operate at high temperatures.
Metals and stones are good conductors of heat because they transport heat quickly, but wood, paper, air, and fabric are poor heat conductors.
Silver is the best heat conductor because it contains the most free electrons in its outer shell, which aids in heat transfer.
Copper is well-known for its ability to carry electricity and heat after silver. This is due to the fact that delocalized electrons within the solid lattice of metals are free to move about within their lattice.
These would operate as heat and electric charge transporters from one end to the other, transforming metal into a good conductor.
Therefore, Copper is the second-best conductor of heat.