Question

What affect did the copper metal in contact with the steel wool have on the rate of corrosion of the iron? If aluminum or magnesium was in contact with a piece of iron how would the rate of corrosion be affected?

Answer 1

The less electrochemically active metals (like copper) increase the rate of corrosion of the iron.
The more electrochemically active metals (like aluminum or magnesium) decrease the rate of corrosion.