In solids, heat is mainly transferred through molecules’ vibrations. This process is called __. *
A radiation
B convection
C conduction
The correct answer and explanation is :
The correct answer is C) conduction.
Explanation:
Conduction is the process by which heat is transferred through direct contact between particles (molecules, atoms, or ions) within a material. In solids, the molecules are closely packed together, allowing them to interact with one another more efficiently compared to gases and liquids. Heat transfer in solids primarily occurs through the vibration of these molecules. When one part of the solid is heated, the molecules at that part gain energy and begin to vibrate more vigorously. These vibrating molecules then collide with neighboring molecules, transferring energy in the form of kinetic energy. The neighboring molecules, in turn, begin to vibrate more intensely, and this process continues, transferring heat through the material. This is how heat spreads from the warmer region to the cooler region of the solid.
This transfer of heat via molecular vibration is a characteristic of conduction and occurs in all states of matter, although it is most efficient in solids due to their closely packed structure. Metals, for example, are excellent conductors of heat because their atoms are arranged in a regular, closely packed structure, and they also have free electrons that help transfer energy more quickly.
In contrast, convection (option B) is the process of heat transfer through the movement of fluids (liquids or gases). It involves the bulk movement of the fluid itself, not just the vibration of particles. Radiation (option A) refers to the transfer of heat in the form of electromagnetic waves (such as infrared radiation) without requiring any medium.
Therefore, conduction is the correct process for the transfer of heat in solids, and it is essential in many everyday processes like cooking, heating, and the functioning of heat exchangers.