Which of the following statements about conduction is true?

The statement regarding conduction that is true is that it occurs through direct contact. Conduction is a mode of heat transfer where thermal energy is transferred between materials that are in direct physical contact with one another. This means that heat moves from one molecule to another without any movement of the material itself; for instance, when you touch a hot surface, the heat transfers from the surface into your skin through direct contact.

In contrast, the other statements do not accurately describe conduction. It does not require the movement of fluids, as that characterizes convection, another form of heat transfer. Regarding heat transfer effectiveness, conduction can be quite effective, especially in solids, where particles are closely packed. Furthermore, while conduction itself can happen alongside chemical reactions (for example, metals conducting heat in a reaction), it is not defined by or specifically related to chemical reactions. Understanding these distinctions is essential for grasping the concepts of thermal energy transfer.