American Meteorological Society Certification (AMS) Practice

Radiation is the correct choice because it refers to the process by which energy is transferred in the form of electromagnetic waves, such as light or infrared radiation. This type of heat transfer does not require a medium or the movement of particles; it can occur through a vacuum, which is why the warmth of the sun can reach Earth despite the vast emptiness of space in between.

In contrast, conduction involves the transfer of heat through direct contact between materials, where particles vibrate and collide, thus transferring energy. Convection is the movement of heat via fluids (liquids or gases) that occurs as warmer, less dense regions rise and cooler, denser regions sink, establishing a circulation pattern. Condensation is a phase change where gas turns into a liquid, and while it is related to heat transfer when considering latent heat, it does not describe a mechanism of heat transfer without the movement of particles.