• Galvanized nails in wood
  
  

Metal Reactions

• Certain metals react with water and acids faster than other metals. Metals are listed according to their reactivity in the Activity Series of Metals. Zinc is more reactive than iron.
  
  

Galvanization

• Galvanization creates a barrier between the nail and the elements. Should the zinc coating become scratched and expose the iron beneath, the zinc will degrade instead of the iron rusting.
  
  

Sacrificial Anode

• The zinc coating acts as a sacrificial anode. A sacrificial anode is a very reactive metal object or coating whose purpose is to corrode and dissolve, sacrificing itself, while a more important or expensive object remains intact.
  
  

Benefits

• Galvanized items corrode 1/10 to 1/30 the rate of ungalvanized items. The zinc develops a layer of corrosion called patina that acts as a sealer and further protects the object.
  
  

Other Uses

• Sacrificial anodes are not only used in galvanized nails but also in boats. Near the boats propeller there is often a large piece of magnesium that dissolves instead of the propeller.