Iron. Iron, when exposed to oxygen, turns into iron oxide - better known as rust.
Chemical.
Rust is a chemical change.
Oxygen turns copper green.
I am quite sure that rust is a chemical change. Rust is caused when oxygen atoms begin bonding with the iron in the nail, which makes it a compound instead of a pure element.
It's called chemical weathering/chemical change. Similar to the physical change of matter, except the chemical composition changes causing it to become something completely different. For example: iron turns to rust, silver tarnishes and copper turns green.
Its is chemical as
Rusting is a chemical change.
gold is an element
Chemical change.
Chemical change.
rust is a chemical change for iron
Rust is a chemical reaction called oxide. When a nail rust, the chemical change is related to the reaction of the metal and oxygen.