Water, especially salt water, is the primary liquid that rusts nails. Rust is iron oxide, which forms when iron comes into contact with oxygen and moisture. Salt water accelerates the rusting process because the salt ions in the water help to break down the protective layer of iron oxide that forms on the surface of the nail.

Other liquids that can rust nails include:

- Vinegar: Vinegar is a mild acid that can dissolve the protective layer of iron oxide on the surface of the nail.

- Lemon juice: Lemon juice is also a mild acid that can dissolve the protective layer of iron oxide on the surface of the nail.

- Bleach: Bleach is a powerful oxidizing agent that can break down the protective layer of iron oxide on the surface of the nail.

- Ammonia: Ammonia is a base that can dissolve the protective layer of iron oxide on the surface of the nail.