Which metal listed is used as a building material alongside steel, aluminum and copper, often for structural or decorative purposes?

• A. Bronze
• B. Cast Iron
• C. Lead
• D. Mercury

Answer: (B)

Cast iron fits as a building material alongside steel, aluminum, and copper because it combines castability with good stiffness and compressive strength. Its ability to be poured into intricate shapes makes it ideal for decorative elements and architectural details like ornamental columns, friezes, railings, and decorative facades, while still providing sturdy bulk where compression is the main stress. Bronze is used for decorative hardware and details but is more expensive and not as common for structural features. Lead and mercury aren’t used for structural building materials—lead has been used in pipes and shielding but is soft and toxic, and mercury is a liquid with no structural role.