What is convection?

Convection refers to the transfer of heat through the movement of fluids, which include liquids and gases. This process occurs because warmer, less dense fluid rises while cooler, denser fluid sinks, creating a continuous circulation pattern that facilitates energy transfer. For example, when air is heated by a fire source, it becomes less dense and rises, while cooler air moves in to take its place, creating convection currents that spread the heat throughout the area. This principle is essential in understanding how heat moves in various environments, particularly in fire dynamics.

The other options illustrate different methods of heat transfer. The first option describes conduction, where energy transfers through direct contact between materials. The second option portrays radiation, the transfer of energy in the form of electromagnetic waves, which can occur in a vacuum. The fourth option refers to conduction again, this time involving heat transfer through solid objects. Each of these processes is distinct from convection, which specifically involves the circulation of fluids to carry energy.