1. Physical change: A change in which a substance undergoes a change in its physical properties.
2. Rust: When pieces of iron is left in the open for sometime, it acquires a film of brownish substance which is called rust.
3. Rusting: The process in which rust is formed.
4. Chemical change: A change in which one or more new substances are formed.
5. Chemical reaction: A chemical change is called chemical reaction.
6. Galvanisation: The process of depositing a layer of zinc on iron is called galvanization.
7. Crystallisation: The process by which large crystals of pure substances are formed from their solutions.