What property of materials determines their ability to be stretched into wires?

The property that determines a material's ability to be stretched into wires is known as ductility. Ductility refers to a material's capacity to undergo significant plastic deformation before rupture or fracture, allowing it to be drawn out into thin wires without breaking. This characteristic is crucial for metals like copper and aluminum, which are commonly used to make electrical wires due to their excellent ductility.

Materials with high ductility can be deformed under tensile stress, which is why they can be transformed into elongated shapes like wires, while maintaining their structural integrity. In contrast, materials that are brittle tend to break without significant deformation when stress is applied, and those with high levels of plasticity may deform but not necessarily into a wire-like form. Malleability specifically refers to the ability of a material to be deformed under compressive stress, such as being hammered into a flat shape, rather than being elongated into a wire. Thus, ductility is the key property that enables materials to be drawn into wires.