Which process describes the transfer of heat through one solid to another?

The transfer of heat through one solid to another is known as conduction. This process occurs when heat is transferred through direct contact between materials. When one solid object has a higher temperature, it can transfer thermal energy to a neighboring solid that has a lower temperature. The heat flow continues until thermal equilibrium is reached—meaning both solids achieve the same temperature.

In practical terms, conduction is most evident in situations such as when a metal spoon is placed in a hot pot; the heat from the liquid soup is transferred to the spoon through direct contact, and the spoon, in turn, becomes warm to the touch. This is a key concept in various applications, including cooking, heating systems, and even in the analysis of fire behavior.

Topics like convection involve the movement of fluids (liquids or gases) carrying heat energy, while radiation refers to heat transfer in the form of electromagnetic waves, which does not require a medium. Hygroscopy, on the other hand, pertains to the ability of a substance to absorb moisture from the air and is not related to heat transfer. Understanding conduction is essential for fire fighters in contexts such as material selection and thermal protection during fire responses.