What best describes a physical change?

• A. Changes appearance of object, doesn't create a new substance
• B. Creates a new substance with different properties
• C. Occurs only at high temperature
• D. Causes a change in chemical composition

Answer: (A)

Physical changes involve altering a material’s form or state without creating a new substance. The key idea is that the substance remains the same at the molecular level even as its appearance, size, shape, or phase changes. That’s why describing a change that only affects how it looks, while keeping the same material, matches a physical change.

Chemical changes, on the other hand, produce substances with different properties because new bonds form or old ones break, changing the composition. Temperature alone doesn’t define a physical change, since many physical changes occur at various temperatures. And a change in chemical composition signals a chemical change, not a physical one.