Matter Homework Packet Name Period Physical and Chemical Changes and Properties of Matter Worksheet Classify the following as chemical change (cc), chemical property (cp), physical change (pc), or physical property (pp). 1. Heat conductivity 2. Silver tarnishing 3. sublimation 4. magnetizing steel 5. length of metal object 6. shortening melting 7. exploding dynamite 8. Combustible 9. Water freezing 10. Wood burning 11. Acid resistance 12. Brittleness 13. Milk souring 14. baking bread Identify the following as being true or false to the left of the sentence. 15. A change in size or shape is a physical change. 16. A chemical change means a new substance with new properties was formed. 17. An example of a chemical change is when water freezes. 18. When platinum is heated, then cooled to its original state, we say this is a physical change. 19. When milk turns sour, this is a physical change because a change in odor does not indicate a chemical change. 20. When citric acid and baking soda mix, carbon dioxide is produced and the temperature decreases. This must be a chemical change. Identify each of the following as a physical or chemical change. 21. You leave your bicycle out in the rain and it rusts. 22. A sugar cube dissolves. 23. Scientist break-up water into oxygen and hydrogen gas. 24. Burning coal for a barbecue. 25. Trimming a bush because it has grown too tall.
The Correct Answer and Explanation is:
Classify as Chemical Change (cc), Chemical Property (cp), Physical Change (pc), or Physical Property (pp):
- Heat conductivity – pp
- Silver tarnishing – cc
- Sublimation – pc
- Magnetizing steel – pc
- Length of metal object – pp
- Shortening melting – pc
- Exploding dynamite – cc
- Combustible – cp
- Water freezing – pc
- Wood burning – cc
- Acid resistance – cp
- Brittleness – pp
- Milk souring – cc
- Baking bread – cc
True or False:
- True – A change in size or shape is a physical change.
- True – A chemical change creates a new substance with new properties.
- False – Water freezing is a physical change, not chemical.
- True – Reversible heating/cooling is a physical change.
- False – Sour milk indicates a chemical change due to new substances forming.
- True – Gas production and temperature change indicate a chemical change.
Identify as Physical or Chemical Change:
- Rusting bicycle – Chemical
- Sugar cube dissolving – Physical
- Breaking water into gases – Chemical
- Burning coal – Chemical
- Trimming a bush – Physical
Explanation
Matter can undergo physical or chemical changes. Physical changes affect the form or appearance of a substance without altering its chemical composition. Examples include melting, freezing, dissolving, and cutting. For instance, water freezing (item 9) or sugar dissolving (item 22) doesn’t produce a new substance, so they are physical changes.
In contrast, chemical changes result in the formation of one or more new substances with different properties. These changes are usually irreversible or require another chemical change to reverse. Burning wood (item 10) or baking bread (item 14) are chemical changes because the original materials are transformed into new substances with different characteristics (like ash, carbon dioxide, or baked dough).
Properties also fall into two categories: physical properties, such as brittleness or length, describe the physical state of a substance without changing its identity. Chemical properties, such as combustibility or acid resistance, describe a substance’s potential to undergo chemical change.
True/false questions reinforce that changes in state or size (like melting or trimming) are physical, while indicators such as gas formation, color change, or odor (like souring milk or rusting) point to chemical changes. For example, when baking soda reacts with citric acid (item 20), the production of gas and temperature drop confirm a chemical reaction has occurred.
Understanding the differences between these types of changes and properties helps us classify and predict matter’s behavior in various scientific and real-world contexts.
