Why does bleach make an iron nail rust?
bleach makes iron rust because it has the ability to change any colored objects. so if you leave any iron in a cup of bleach you will see the iron starting to rust.
A nail made out of just iron will rust really fast if it is exposed to oxygen. Nails available now, are galvanized nail which has a coating of copper metal on the surface of iron nail. This slows down process of rusting. Exposing a iron nail to water and other acidic environment along with oxygen, can make a nail rust pretty fast.
The rusty nail weighs more. Rust is iron oxide, a molecule consisting of iron and oxygen. The mass of the iron in the rust molecules comes from the original nail, but the mass of the oxygen has come from the air. When rust forms on iron, the mass of the iron object is increased by the mass of the oxygen that has combined with some of the iron.