Write the definition of thermal conduction and explain thermal conduction in solid bodies.

(N/A) Thermal Conduction: Conduction is the mechanism of heat transfer between two adjacent parts of a body due to a temperature difference between them.
In solid bodies,thermal conduction occurs primarily through two mechanisms: the vibration of atoms or molecules about their mean positions and the movement of free electrons.
When one end of a metallic rod is placed in a flame,the atoms at that end gain kinetic energy and vibrate more vigorously. These vibrations are passed on to neighboring atoms through intermolecular forces,effectively transferring energy along the rod.
In metals,the presence of a large number of free electrons significantly enhances this process. These electrons gain energy at the hot end and move rapidly toward the cooler end,colliding with atoms and transferring energy,which makes metals excellent thermal conductors.
Gases are generally poor thermal conductors,while liquids have thermal conductivities intermediate between solids and gases.