Answer:

1) The nail which is moisten with water will become rusty while the nail with oil don't get affected.

2) Salt will get deposited at the surface of the plate.

Explanation:

1) As the nail with water react with oxygen present in it and develop a layer of oxide, while the oiled nail is not exposed to air or water, hence it won't get rusted.

2) As the water present in the solution will evaporate, the salt present in the solution will remain on the plate.