14. milk souring p/c c
15. gasoline burning p/c c
16. ice melting p/c p
17. lighting a match p/c c
18. water evaporating p/c p
19. chopping wood p/c p
20. burning wood p/c c
21. breath fogging a mirror p/c p
22. cooking an egg p/c c

Question

14. milk souring  p/c c
15. gasoline burning  p/c c
16. ice melting  p/c p
17. lighting a match  p/c c
18. water evaporating  p/c p
19. chopping wood  p/c p
20. burning wood  p/c c
21. breath fogging a mirror  p/c p
22. cooking an egg  p/c c

Accepted Answer

To determine if a change is physical (P) or chemical (C), we use the definitions:
- **Physical change**: Alters form/appearance, not composition (no new substance).
- **Chemical change**: Forms new substances (involves reactions, energy changes, or irreversibility).

### 14. Milk souring
Milk sours due to bacterial fermentation (lactose → lactic acid), forming a new substance.
**Answer**: C

### 15. Gasoline burning
Burning gasoline (hydrocarbons + O₂ → CO₂ + H₂O) produces new substances.
**Answer**: C

### 16. Ice melting
Ice (solid H₂O) becomes liquid H₂O—no new substance, just state change.
**Answer**: P

### 17. Lighting a match
Match combustion (phosphorus/sulfur + O₂ → new compounds) forms new substances.
**Answer**: C

### 18. Water evaporating
Liquid H₂O → gaseous H₂O—state change, no new substance.
**Answer**: P

### 19. Chopping wood
Wood is physically split into smaller pieces—no new substance.
**Answer**: P

### 20. Burning wood
Wood (cellulose) burns to CO₂, H₂O, ash—new substances formed.
**Answer**: C

### 21. Breath fogging a mirror
Warm breath (H₂O vapor) condenses to liquid H₂O on the mirror—state change, no new substance.
**Answer**: P

### 22. Cooking an egg
Egg proteins denature (structural change, new arrangement) and coagulate—chemical change.
**Answer**: C

### Final Answers (P = Physical, C = Chemical):
14. C
15. C
16. P
17. C
18. P
19. P
20. C
21. P
22. C

Sovi.AI - AI Math Tutor

QUESTION IMAGE

Question

Explanation:

14. Milk souring

Answer:

15. Gasoline burning