What mechanism describes conduction?

Conduction refers specifically to the process of heat transfer that occurs through direct contact between molecules. In this mechanism, thermal energy is transferred from one molecule to another within the same phase of matter (such as solid, liquid, or gas) without any motion of the material as a whole. For example, when a metal rod is heated at one end, the heat travels through the rod as the vibrating molecules collide with their neighboring molecules, transferring energy in the process. This explanation highlights the nature of conduction as a microscopic interaction between particles, emphasizing how energy moves through a substance without the bulk movement of the substance itself.

Other options describe different phenomena. The movement of air carrying heat pertains to convection, where warmer air rises and cooler air sinks, creating a continuous movement and mixing of fluid. The burning of materials signifies a combustion reaction, which involves chemical changes and the release of energy rather than direct thermal transfer. Lastly, evaporation involves the transition of liquid to gas, which is a different physical process not directly related to the conduction of heat within a solid or fluid.