Which metals tarnish quickly?

A. Hi Mark. "Quickly" is relative. Aluminum and magnesium and zinc are active metals which tarnish quite quickly. Copper and nickel are more noble and will tarnish more slowly. If you had a sulfide-free environment, silver would probably tarnish slowly, but there is enough sulfide in the atmosphere that silver tarnishes pretty quickly. All metals except the precious metals like gold, platinum, and rhodium tarnish. The reason you see gold plating on small low voltage connections like the lightning connector for an iPhone is because the tarnish on non precious metals would interfere with the signals.

Your question is still abstract because it gives us no clue where you're trying to go with the information or why. The reason it matters is that there are 1001 ifs, ands and buts that need to be considered in the general case, but probably only a couple that actually apply to a particular situation. Unfortunately, we don't know which couple they are :-)

One reason textbooks are hundreds of pages long is because they attempt to provide general answers to such questions including all those ifs, ands, and buts.

Luck and Regards,