Which metal is used in building construction primarily as a coating to protect metal parts from rust and corrosion?

• A. Zinc
• B. Manganese
• C. Copper
• D. Gypsum

Answer: (A)

Zinc is used as a protective coating on metal in construction, a process known as galvanizing. It serves as both a barrier to moisture and as a sacrificial anode, meaning zinc corrodes first, protecting the underlying steel from rust and corrosion. Even if the coating is scratched, the remaining zinc still provides galvanic protection, delaying rust. This is why structural steel, nails, bolts, and rebar are commonly hot-dip or electrogalvanized. In contrast, manganese is mainly an alloying element in steel, copper is corrosion-resistant but not the standard coating for structural protection, and gypsum is a non-metal used in drywall, not as a coating.