Zinc is more reactive than iron or steel and thus will attract almost all local oxidation until it completely corrodes away. A protective surface layer of oxide and carbonate (Zn
5(OH)
6(CO
3)
2) forms as the zinc corrodes. This protection lasts even after the zinc layer is scratched but degrades through time as the zinc corrodes away. The zinc is applied electrochemically or as molten zinc by hot-dip galvanizing or spraying. Galvanization is used on chain-link fencing, guard rails, suspension bridges, lightposts, metal roofs, heat exchangers, and car bodies. COUNT 4
QSN1 What two compounds is zinc more reactive than? ANS1 iron or steel QSN2 What forms as zinc corrodes? ANS2 protective surface layer of oxide and carbonate QSN3 How is zinc applied? ANS3 electrochemically or as molten zinc QSN4 What is used on many common items, such as chain link fences? ANS4 Galvanization