Which heat transfer mode is energy transfer by electromagnetic waves through empty space?

Which heat transfer mode is energy transfer by electromagnetic waves through empty space?

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

Answer: (A)

Radiation is energy transfer by electromagnetic waves through empty space. EM waves don’t need a medium, so they can travel through a vacuum, like sunlight warming the Earth across space. Conduction needs direct contact with matter, as heat moves by particle interactions in solids, liquids, or gases. Convection relies on the bulk movement of a fluid to carry heat. Evaporation involves a phase change and associated energy, not the transmission of heat across empty space. So the energy transfer through empty space is radiation.

Radiation is energy transfer by electromagnetic waves through empty space. EM waves don’t need a medium, so they can travel through a vacuum, like sunlight warming the Earth across space. Conduction needs direct contact with matter, as heat moves by particle interactions in solids, liquids, or gases. Convection relies on the bulk movement of a fluid to carry heat. Evaporation involves a phase change and associated energy, not the transmission of heat across empty space. So the energy transfer through empty space is radiation.