What type of energy transfer occurs by the movement of a medium?

The correct answer, convection, refers to the transfer of heat through the movement of a medium, typically a fluid such as a liquid or gas. In convection, warmer, less dense areas of the fluid rise while cooler, denser areas sink, creating a continuous cycle of movement. This process allows heat to be distributed evenly throughout the medium.

Consider everyday examples: when you heat a pot of water on the stove, the water at the bottom warms up, rises to the top, and is replaced by cooler water from above, illustrating convection in action. This mechanism is essential in understanding not just basic science but also meteorological phenomena, heating systems, and even cooking.

In contrast, conduction involves the direct transfer of heat through a substance without the movement of the material itself, and radiation transfers energy through electromagnetic waves without needing a medium. Induction typically refers to the induction of electric or magnetic fields, which is unrelated to thermal energy transfer. Thus, convection is uniquely characterized by the movement of a medium to facilitate energy transfer.