Air, iron and water will cause the iron to rust.
When iron gets wet or comes into contact with water, it is likely to rust. However, some iron products are coated with substances that help prevent rust.
Iron is one of the most common substances on earth. If the sand is rich in iron (or other magnetic particles), then it will be attracted to a magnet.
Of those two substances, water has.
Iron oxide (Fe2O3) in insoluble in water.
A water solution of iron sulfate is obtained.
If you simply mix iron filings and sulfur crystals together, you get a mixture. The iron keeps the properties of iron (including its ability to be magnetized), and the sulfur retains the properties of sulfur. This mixture can be easily separated mechanically by simply passing a magnet nearby, which will magnetize and attract the iron filings. If you combine the two using heat, however, they iron and sulfur will chemically react to form the compound iron sulfide. This compound will have properties different from either the sulfur or iron. A magnet will no long separate the two (although it might attract excess iron that was not combined in the reaction). This experiment is meant to distinguish the properties of substances combined in mixtures versus substances combined as chemical compounds.
Rusting is possible in the presence of oxygen and water.
Oxygen and Water
Yes, rust happens to iron nail though it is kept in distilled water.
The salt dissolves in the water and the iron does not.
Lead, iron and water
Iron oxide (Fe2O3) in insoluble in water.