The following items will test your grasp of the material covered in this lesson. There is only one correct answer
for each item. When you complete the exercise, check your answers with the answer key that follows. If you
answer any item incorrectly, study again that part of the lesson which contains the portion involved.
What is one of the reasons that corrosion occurs?
A difference in potential.
It does not occur.
Energy is subtracted through each step in the chain to shape the end product.
There was no oil in it.
What are the four causes of external corrosion?
Similar metal, similar soil, Nondifferential aeration, Direct current migration
Dissimilar metal, dissimilar soil, differential aeration, stray current migration
Dissimilar metal, similar soil, differential aeration, stray current migration
Similar metal, dissimilar soil, nondifferential aeration, direct current migration
An insulating barrier placed between a metal and a surrounding electrolyte, is known as a?