Heat traveling from one end of a steel beam to the other end is an example of:

Heat traveling from one end of a steel beam to the other end is an example of conduction because this process involves the direct transfer of heat through a material without the movement of the material itself. In solids, particularly metals like steel, heat is transferred as vibrational energy is passed from one molecule to another.

In this scenario, the thermal energy from the warmer end of the steel beam is conducted to the cooler end through molecular collisions and interactions. This transfer occurs most efficiently in solid materials, which is why metals such as steel are often used in applications that require effective heat conduction.

The other processes mentioned, such as convection and radiation, do not apply to this situation. Convection involves the transfer of heat through fluids (liquids and gases) caused by the motion of the fluid, where warmer areas rise and cooler areas sink. Radiation involves the transfer of heat through electromagnetic waves, which can occur in a vacuum and does not require a medium. Oxidation refers to a chemical reaction involving the combination of a substance with oxygen, which is unrelated to heat transfer. Thus, conduction is the only appropriate term for the heat movement described in the question.