Which is an example of a physical change?

• A. Rust forming on iron.
• B. Gasoline burning.
• C. Ice melting.
• D. Baking a cake.

Answer: (C)

Physical changes involve a change in a material’s form or state without making a new substance. Ice melting fits this perfectly: solid water changes into liquid water when it absorbs heat, but the substance is still H2O. The identity of the material doesn’t change, only its phase, and you can reverse it by freezing the water again.

By contrast, rust forming on iron becomes a new substance—iron oxide with different properties—so that’s a chemical change. Gasoline burning also changes into new chemicals like carbon dioxide and water, releasing energy, which is another chemical change. Baking a cake involves chemical reactions that create new substances, even though some physical changes happen along the way.

So, ice melting is the best example of a physical change because it changes state without altering the substance’s identity.