Final answer:
Copper and aluminum are used in solar collector plates due to their high thermal conductivity, while steel is less suitable due to its lower efficiency in heat transfer and potential for corrosion.
Step-by-step explanation:
The materials commonly used for constructing solar collector plates, such as copper and aluminum, are selected for their high thermal conductivity, which allows them to effectively absorb and transfer heat. These metals have many free electrons that can transport thermal energy efficiently, making them excellent for use in solar collectors.
Copper is also known for its good electrical conductivity, ductility, and is used in various alloys for different applications. Aluminum is often alloyed to increase its strength while maintaining its light weight, making it useful for various engineering applications. Answer choice (a) is correct because these materials are chosen for their conductivity, and steel, while also conductive, is generally not as efficient as copper or aluminum in transferring heat and is also prone to corrosion, which can affect its performance in solar collection systems.