Question

which statement best compares conduction, convection, and radiation?
○ convection and radiation transfer thermal energy through matter only, and conduction transfers thermal energy through both matter and empty space.
○ radiation and conduction transfer thermal energy through matter only, and convection transfers thermal energy through both matter and empty space.
○ convection and conduction transfer thermal energy through matter only, and radiation transfers thermal energy through both matter and empty space.
○ conduction, convection, and radiation transfer thermal energy through both matter and empty space.

Explanation:

To solve this, we recall the mechanisms of heat transfer:

• Conduction: Requires direct contact between particles (through matter, e.g., metal spoon heating in a flame).
• Convection: Involves heat transfer by movement of fluids (liquids/gases, so through matter).
• Radiation: Transfers heat via electromagnetic waves (can travel through empty space, e.g., sun’s heat to Earth).

Now, analyze each option:

• First option: Wrong (convection needs matter; radiation doesn’t need matter).
• Second option: Wrong (radiation doesn’t need matter; convection needs matter).
• Third option: Correct. Conduction (matter) and convection (matter) transfer through matter only; radiation (waves) transfers through matter and empty space.
• Fourth option: Wrong (conduction and convection need matter, radiation can go through empty space, but not all three transfer through both).

Answer:

C. Convection and conduction transfer thermal energy through matter only, and radiation transfers thermal energy through both matter and empty space.