Which phenomenon is described as the transfer of radiant energy through space, such as infrared heat, without a medium?

Which phenomenon is described as the transfer of radiant energy through space, such as infrared heat, without a medium?

• A. Radiation
• B. Conduction
• C. Convection
• D. Evaporation

Answer: (A)

Radiation is the transfer of energy by electromagnetic waves through space, and it does not require any medium. This is why heat from the sun or a campfire can reach you across a vacuum or air—the energy travels as infrared and other wavelengths directly to you. Conduction needs physical contact with a material, transferring energy through the material itself. Convection depends on the movement of a fluid to carry heat. Evaporation is a phase change at a surface, not a method of transferring heat through space.

Radiation is the transfer of energy by electromagnetic waves through space, and it does not require any medium. This is why heat from the sun or a campfire can reach you across a vacuum or air—the energy travels as infrared and other wavelengths directly to you. Conduction needs physical contact with a material, transferring energy through the material itself. Convection depends on the movement of a fluid to carry heat. Evaporation is a phase change at a surface, not a method of transferring heat through space.