What is a key characteristic of aluminum wire compared to copper wire?

Aluminum wire has a key characteristic of being lower in weight compared to copper wire. This makes it advantageous for certain applications, especially in overhead electrical transmission lines where reducing weight can ease structural demands and lower installation costs. Although aluminum does have a lower conductivity than copper, it is still utilized effectively by increasing the cross-sectional area to compensate for this difference, allowing for efficient transmission of electricity even with its heavier weight factored in.

In contrast, copper is known for its superior conductivity and flexibility, making it a preferred choice for various applications despite its greater weight. The other characteristics noted, such as flexibility and melting points, do not accurately define aluminum wire as distinctly compared to copper wire. Therefore, identifying lower weight as the key characteristic highlights an important aspect of the material's performance in electrical applications.