Free Printable Physical and Chemical Properties and Changes Worksheets - Free Printable

Explanation:
We need to label each everyday occurrence as either a Physical (P) change or a Chemical (C) change.

🔹 A physical change means the substance’s form or state changes, but its chemical identity stays the same. No new substances are formed. Examples: melting, freezing, breaking, dissolving (if no reaction), evaporation, cutting.

🔹 A chemical change means a new substance is formed — usually with signs like color change, gas production, heat/light release, or irreversible change. Examples: burning, rusting, digestion, cooking, tarnishing.

Now go through each item one by one:

1. Crushing a rock → Just breaks into smaller pieces; still rock. → P
2. Digesting food → Enzymes break down food into new molecules (e.g., sugars, amino acids). → C
3. Water evaporating → Liquid → gas (H₂O still H₂O). → P
4. Fireworks exploding → Chemical reactions produce light, sound, gases, new compounds. → C
5. Getting a haircut → Hair cut, but hair is still hair. → P
6. An ice cube melting → Solid → liquid water. Same substance. → P
7. A candle burning → Wax reacts with oxygen → CO₂ + H₂O + heat/light. New substances. → C
8. Salt dissolving in water → NaCl separates into ions, but can be recovered unchanged. No new substance. → P
9. Silver tarnishing → Silver reacts with sulfur to form silver sulfide (black layer). → C
10. Glass breaking → Shape changes, material same. → P
11. Hair bleaching → Chemicals (like hydrogen peroxide) break down melanin pigment → new substances. → C
12. A bicycle rusting → Iron + O₂ + H₂O → iron oxide (rust). New substance. → C
13. Frying an egg → Heat denatures proteins — irreversible change, new structure/substances. → C
14. Baking soda reacting with vinegar → NaHCO₃ + CH₃COOH → CO₂ gas + water + sodium acetate. → C
15. Oil mixing with water → Doesn’t dissolve; just separates. No reaction. Physical mixture. → P
16. Cutting grass → Just shortening blades; still grass. → P
17. Butter melting → Solid fat → liquid fat. Same molecules. → P
18. Ethanol evaporating → Liquid → vapor. Still C₂H₅OH. → P
19. Grass growing → Photosynthesis makes new plant material (glucose, cellulose, etc.). → C
20. A tire inflating → Air pushed in; volume changes, no new substances. → P

Let me double-check tricky ones:
- Salt dissolving: physical (reversible, no bond breaking beyond ionic dissociation).
- Oil + water: immiscible, physical.
- Hair bleaching: definitely chemical (oxidation of pigment).
- Grass growing: biological process involving chemical reactions → chemical change.

All seem correct.

Final Answer:
1. P
2. C
3. P
4. C
5. P
6. P
7. C
8. P
9. C
10. P
11. C
12. C
13. C
14. C
15. P
16. P
17. P
18. P
19. C
20. P