Which of the following is a method of heat transfer in gases and liquids?

Convection is a method of heat transfer that occurs in fluids, such as gases and liquids, through the movement of the fluid itself. When a fluid is heated, it becomes less dense and rises, while cooler, denser fluid moves in to replace it. This creates a circulation pattern that effectively transfers heat throughout the fluid.

In the case of convection, the motion of the fluid plays a critical role in distributing heat. For example, when water is heated in a pot, the hot water at the bottom rises to the surface, and cooler water moves down to take its place, leading to a continuous flow that distributes heat evenly throughout the water.

This concept is distinct from conduction, which is the transfer of heat through direct contact between materials, primarily in solids. Radiation refers to the transfer of energy through electromagnetic waves and does not require a medium, allowing heat to be transferred through a vacuum. Absorption is a process where materials take in energy, but it does not represent a method of heat transfer like convection does.