What process describes the flow of heat from molecule to molecule within a substance in direct contact with another body?

The correct choice identifies conduction as the process by which heat transfers from one molecule to another within a substance that is in direct contact with another body. This phenomenon occurs primarily in solids, where molecules are tightly packed together, facilitating efficient energy transfer through direct molecular interactions. When one part of the substance is heated, its molecules move more vigorously and collide with adjacent, cooler molecules, transferring thermal energy in the process. This continues throughout the material until thermal equilibrium is reached.

In contrast, convection involves the transfer of heat through the movement of fluids (liquids or gases), where warmer, less dense regions rise and cooler, denser regions sink, creating a circulation pattern. Specific heat refers to the amount of energy required to change the temperature of a unit mass of a substance by one degree, but it does not describe the method of heat transfer itself. The latent heat of fusion pertains to the energy required to change a substance from solid to liquid at its melting point, which also does not relate to molecular heat transfer in direct contact.