Rust is oxidized iron (aka Ferric Oxide, or FeO2), or iron that has been exposed sufficiently to oxygen. It can take anywhere from hours to form in a damp or wet environment, to years in a dry one.
Copper doesn't rust
If they are an alloy, they will eventually rust.
How long will it t take a quarter to rust in fresh water
a long time
It depends on the quality of the nail. If it is painted it Amy take long to rust. In general it may take a month or so for the nail to rust.
a week it take or two
50 years
5 months
Cannot rust. No oxygen or water.
about 14 days
it will probably take at least 5 minutes for a needle to rust unless it is copper.
The oxygen dissolved in the water combines with the iron to form iron oxide, or rust (Fe2O3H2O).