Which statement about conduction is correct?

Which statement about conduction is correct?

• A. Heat transfer by radiation
• B. Heat transfer through currents caused by temperature differences
• C. Heat transfer through a vacuum
• D. Heat transfer through direct contact

Answer: (D)

Conduction is heat transfer through direct contact, where energy moves from hotter particles to cooler ones by interactions between neighboring particles. In solids, this happens as atoms vibrate and pass energy to adjacent atoms; in metals, free electrons quickly shuttle energy from the hot region to the cooler region. This mode requires matter to be in contact—no conduction can occur in a vacuum because there’s no medium for the particles to transfer energy between. Other ways heat can move are convection, which involves the bulk movement of fluids carrying energy, and radiation, which travels energy through space via electromagnetic waves without contact. So, describing heat transfer through direct contact captures the essence of conduction. A common example is a metal rod warming along its length when one end is placed in hot water, transferring heat through the rod to the cooler end.

Conduction is heat transfer through direct contact, where energy moves from hotter particles to cooler ones by interactions between neighboring particles. In solids, this happens as atoms vibrate and pass energy to adjacent atoms; in metals, free electrons quickly shuttle energy from the hot region to the cooler region. This mode requires matter to be in contact—no conduction can occur in a vacuum because there’s no medium for the particles to transfer energy between. Other ways heat can move are convection, which involves the bulk movement of fluids carrying energy, and radiation, which travels energy through space via electromagnetic waves without contact. So, describing heat transfer through direct contact captures the essence of conduction. A common example is a metal rod warming along its length when one end is placed in hot water, transferring heat through the rod to the cooler end.