- A hammer often is made of metal
- When a metal rusts , that metal becomes flaky on the surface
- So, when a hammer rusts, the hammer will becom flaky on the surface

- When a hammer rusts, the hammer will becom flaky on the surface
- Kim's hammer is flaky on the surface
- Therefore, the hammer has rusted

- The hammer has rusted
- Rust forming is a kind of chemical change
- Hence, the hammer has undergone a chemical change

Therefore, the hammer has undergone a chemical change
Question
Kim lost her hammer outside. When she found it a few months later, some parts of the metal were covered with flaky, brown rust. Which type of change occurred when rust formed on the hammer?

Context
- Kim's hammer is flaky on the surface 
- A hammer often is made of metal 
- Rust forming is a kind of chemical change 
- When a metal rusts , that metal becomes flaky on the surface