Answer :
Final answer:
The evacuated space in a thermos bottle minimizes heat transfer by conduction, convection, and radiation using a combination of a vacuum, reflective coatings, and proper insulation. So, the correct answer is e) conduction, convection, and radiation.
Explanation:
The space between the inner walls of a thermos bottle is evacuated to minimize heat transfer by conduction, convection, and radiation. This design is intentional to maintain the temperature of the contents for as long as possible. In a thermos, conduction is minimized because the vacuum between the walls prevents the direct transfer of heat via contact. Convection is also inhibited as the vacuum stops fluid (air) movement which usually carries heat. Meanwhile, radiation is discouraged by the reflective surfaces of the bottle, bouncing heat back and forth rather than allowing it to pass out of the thermos.
The design of a thermos bottle includes multiple elements that work together to slow heat transfer. For example, the silvering of the walls mitigates radiation loss by reflecting thermal energy, while the long glass neck reduces heat escape by conduction. The rubber support and air layer provide additional insulation, and the stopper traps heat within the bottle. Collectively, these parts ensure that the thermos effectively reduces all three forms of heat transfer, making the process nearly adiabatic where the temperature difference is minimal and energy transfer is predominantly by work.
