Galvanization is a process used to protect iron or steel from rusting by applying a protective zinc coating. The zinc layer acts as a sacrificial anode, meaning it will corrode instead of the underlying metal, thus preventing rust formation. This is particularly important for structures exposed to the elements, like fencing, nails, and various construction materials.

The key reasons zinc is used are:

• It forms a protective layer of zinc carbonate on the surface when exposed to air, which prevents further corrosion.
• Even if the coating is scratched, the zinc will still protect the iron sacrificially.
• It is relatively inexpensive and provides long-lasting protection.

While other metals like chromium (Cr) can be used for plating (a process called chrome plating), lead (Pb) is used in some specific coatings but is toxic, and copper (Cu) is not used for sacrificial protection of iron, zinc is the standard and most effective metal for galvanization.

Final Answer: The correct option is Zn (Zinc).

Related Topics & Formulae

Electrochemical Series: The reactivity of metals determines which metal will act as a sacrificial anode. Zinc is more reactive than iron (lies above iron in the electrochemical series), so it corrodes preferentially.

Corrosion (Rusting): The chemical reaction for the rusting of iron is: $4\mathrm{Fe}+3O_2+6H_{2}O\to 4\mathrm{Fe}{\left(OH\right)}^3$

Sacrificial Protection: The principle behind galvanization. The overall reaction at the anode (zinc) is: $\mathrm{Zn}\to {\mathrm{Zn}}^{2+}+2e^{-}$