Which one of the following pairs of metals are very good conductors of heat?

Metals are generally efficient conductors of heat due to the presence of free electrons. Among all metals, silver and copper are identified as the best conductors of heat [1]. Silver possesses the highest thermal conductivity, approximately 406-429 W/m·K, followed closely by copper at approximately 385-401 W/m·K. These properties make them ideal for high-performance thermal applications, such as heat sinks, electrical wiring, and cooking utensils. In contrast, metals like lead and mercury are characterized as comparatively poor conductors of heat [1]. For instance, lead has a thermal conductivity of about 34.7 W/m·K, while mercury's conductivity is significantly lower at approximately 8.3 W/m·K. Therefore, the pair consisting of silver and copper represents the most effective thermal conductors among the given options.

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 3: Metals and Non-metals > List the metals whose wires you have seen in daily life. > p. 38