Galvanization offers barrier and sacrificial corrosion protection

Steps:

• Galvanization coats iron with zinc to block oxygen and moisture from reaching the iron surface.
• Zinc is more reactive than iron, so it oxidizes preferentially if the coating is damaged.
• This sacrificial action protects the iron from rusting by corroding zinc instead.
• Thus, it combines barrier (intact coating) and sacrificial (damaged coating) mechanisms.

Why B is correct:

• By definition, galvanization provides barrier protection via the zinc layer and sacrificial anodic protection since zinc's standard electrode potential (-0.76 V) is more negative than iron's (-0.44 V), making zinc corrode first.

Why the others are wrong:

• A: Galvanizing deposits a zinc coating, not forming an alloy like steel.
• C: Zinc's reactivity adds sacrificial protection beyond just a barrier.
• D: The intact zinc layer acts as a barrier, not solely sacrificial.

Final answer: B