Question

classifying changes
identify the type of change or changes that apply to each description by writing p for physical change,
c for chemical change, and b for both types of changes on the appropriate line.

1. ______ involves a change in energy; either added or removed.

10.______ a new substance is produced.
11.______ a substance changes form or appearance but remains the same substance.
12.______ melting an ice cube is an example.
13.______ rusting metal is an example.

Explanation:

• For question 9: Both physical (e.g., melting - heat added) and chemical (e.g., combustion - heat released) changes involve energy change.
• For question 10: Production of a new substance is the key characteristic of a chemical change.
• For question 11: A change in form/appearance with the same substance is a physical change.
• For question 12: Melting ice (solid - liquid, same \(H_2O\)) is a physical change.
• For question 13: Rusting (iron + oxygen → rust, new substance) is a chemical change.

Answer:

1. B
2. C
3. P
4. P
5. C