Which of these terms defines the process of heat transfer through a liquid or gas?

The term that defines the process of heat transfer through a liquid or gas is convection. This process involves the movement of fluid, whether it be a liquid or a gas, which carries the thermal energy from one location to another. As the fluid heats up, it becomes less dense and tends to rise, while cooler, denser fluid sinks. This creates a circulation pattern that transfers heat throughout the fluid.

In contrast, conduction refers to heat transfer through a solid material where thermal energy moves from high-temperature areas to lower-temperature areas without the movement of the material itself. Radiation is a different mechanism of heat transfer that does not require a medium; it involves the emission of energy in the form of electromagnetic waves. Diffusion pertains to the movement of particles from an area of high concentration to an area of low concentration, which is not specifically focused on heat transfer.

Understanding convection is critical in applications involving heating and cooling systems, as well as in various natural phenomena like weather patterns and ocean currents.