Heat conduction is illustrated by which of the following examples?

Heat conduction refers to the process of heat transfer through a material without the movement of the material itself. This transfer occurs via direct contact between molecules, allowing energy to pass from one molecule to another.

In the context of the provided examples, the flow of heat through a copper bar serves as a classic illustration of conduction. Copper is an excellent conductor of heat because its atoms allow energy to be transferred quickly between them. When one end of the copper bar is heated, the heat travels along the length of the bar, demonstrating the effectiveness of conduction as the kinetic energy of the vibrating atoms is transmitted across the material.

The other options do not represent heat conduction in the same way. Heat rising in a room relates to convection, where warmer, lighter air moves upwards, creating a cycle of air movement. Warm air mixing with cold air also illustrates convection, as the two air masses move and allow for thermal exchange. Heat transfer through a pump involves mechanical movement and does not pertain to heat transfer via direct molecular interaction within a solid medium.