Final answer:
The element that is magnetic and commonly used for outdoor stair railings and other structural purposes is iron.
The right answer is a. Iron
Step-by-step explanation:
The metallic element in question that is magnetic and used extensively for structural purposes, such as outdoor stair railings, is iron. Iron is a versatile structural material common in everyday items, ranging from automotive components to the construction industry.
Its properties, such as being magnetic, shiny, and an excellent conductor of heat and electricity, make it ideal for these applications. Moreover, only a few materials like iron, cobalt, and nickel show strong magnetic effects and are referred to as ferromagnetic.
Because of these properties, iron is used not only in outdoor railings but also in tools, buildings, and infrastructure.
The right answer is a. Iron