Gold and silver aren't corroded in the presence of moist air because:
Silver and gold are the elements present at the bottom of the reactivity series. This implies that the two elements do not easily react with other elements.
This decline in reactivity is due to the high ionization energies.
They cannot form bonds with oxygen, so they do not rust easily.
Therefore, gold and silver don't corrode in the presence of moist air as they would not react with the water or air.