Final answer:
Iron is a ferromagnetic, metallic element widely used in construction, such as in outdoor stair railings, due to its strength, magnetic properties, and structural reliability.
Step-by-step explanation:
The element being referred to as a magnetic, metallic element used extensively for structural purposes, such as in outdoor stair railings, is iron. Iron is one of the many transition metals that exhibit ferromagnetic properties, meaning it is strongly attracted to magnets and can be magnetized itself. This property is central to its use in magnetic applications, and its structural utility derives from its strength and abundance. Ferromagnetic materials, of which iron is the most common, are often utilized in construction and architecture due to their durability and load-bearing capabilities.
Additionally, the wide range of applications for transition metals includes uses in electronics, monetary systems, catalysts in chemical reactions, batteries, and even in biological systems such as hemoglobin in blood. Outdoors stair railings, in particular, benefit from iron's robustness and ability to withstand environmental elements when treated or alloyed to prevent corrosion.