Air is both a good thermal insulator and conductor. a. True b. False
The Correct Answer and Explanation is:
ChatGPT said:
Correct Answer: b. False
Air cannot be considered both a good thermal insulator and a good thermal conductor at the same time. These two properties are essentially opposites in terms of thermal behavior.
Air is primarily a poor thermal conductor, which makes it a good thermal insulator. A thermal insulator is a material that resists the flow of heat. Because air molecules are far apart compared to solids or liquids, the transfer of heat through conduction occurs very slowly. This is the reason air is used in insulation materials such as foam, fiberglass, and double-glazed windows. These products trap air in small pockets to limit heat transfer.
In contrast, a thermal conductor is a material that allows heat to pass through it easily. Metals such as copper and aluminum are good examples. In these materials, free electrons move easily and transfer energy quickly between atoms, facilitating fast heat conduction.
Air, however, lacks such free-moving particles. It conducts heat mainly through molecular collisions, which occur infrequently due to the low density of air. As a result, its thermal conductivity is very low—approximately 0.024 W/m·K at room temperature, which is much less than metals, and even less than water.
Although air can transfer heat through convection, especially when in motion, this does not make it a good thermal conductor. Convection is a different mode of heat transfer that relies on fluid movement rather than direct conduction through stationary molecules.
In summary, air is a good thermal insulator because it resists the flow of heat due to its low density and poor conductive properties. Therefore, saying air is both a good insulator and a good conductor is scientifically incorrect.
