How do gas molecules transfer heat from a warmer region to a cooler region?

Gas molecules transfer heat from a warmer region to a cooler region primarily through two mechanisms: convection and conduction.12

Convection

Convection is a rapid process involving the physical movement of a heated gas. When a gas is heated, its molecules move faster and spread farther apart, causing the gas to expand and become less dense. Due to increased buoyancy, this warmer, less dense gas rises, while cooler, denser gas sinks to replace it. This continuous cycle creates convection currents that distribute heat throughout the gas.13

Conduction

Conduction involves the transfer of energy between adjacent molecules through collisions. In this process, faster-moving (warmer) molecules collide with slower-moving (cooler) molecules, transferring kinetic energy during these interactions. While conduction occurs in gases, it is generally a slower process compared to convection. The rate of energy flow via conduction is proportional to the temperature difference across the fluid, as described by Fourier’s law.1456