Question

something looks, but havent made a new substance, a physical change (p) has occurred. if the substance has been changes into another substance, a chemical change (c) has occurred.

1. an ice cube is placed in the sun. later there is a puddle of water. later still the puddle is gone.
2. two chemical are mixed together and a gas is produce.
3. a bicycle changes color as it rusts.
4. a solid is crushed to a powder.
5. two substances are mixed and light is produced.
6. a piece of ice melts and reacts with sodium.
7. mixing salt and pepper.
8. chocolate syrup is dissolved in milk.
9. a marshmallow is toasted over a campfire.
10. a marshmallow is cut in half.

Explanation:

To solve this, we determine if each change is physical (P, no new substance) or chemical (C, new substance):

1. An ice cube in the sun

• Ice melts to water (same substance, state change).
• Classification: P

2. Two chemicals mixed, gas produced

• Gas production (new substance) indicates a chemical reaction.
• Classification: C

3. Bicycle rusts

• Rust (iron oxide) is a new substance (oxidation).
• Classification: C

4. Solid crushed to powder

• Only shape changes (same substance).
• Classification: P

5. Two substances mixed, light produced

• Light production (e.g., combustion) means a chemical reaction.
• Classification: C

6. Ice melts and reacts with sodium

• Reaction with sodium (new substance formed) is chemical.
• Classification: C

7. Mixing salt and pepper

• No reaction, just mixing (same substances).
• Classification: P

8. Chocolate syrup dissolved in milk

• Dissolving (no new substance, physical mixing).
• Classification: P

9. Marshmallow toasted

• Toasting causes burning (new substances, chemical change).
• Classification: C

10. Marshmallow cut in half

• Only shape changes (same substance).
• Classification: P

Final Answers (row-wise):

1. P
2. C
3. C
4. P
5. C
6. C
7. P
8. P
9. C
10. P

Answer:

To solve this, we determine if each change is physical (P, no new substance) or chemical (C, new substance):

1. An ice cube in the sun

• Ice melts to water (same substance, state change).
• Classification: P

2. Two chemicals mixed, gas produced

• Gas production (new substance) indicates a chemical reaction.
• Classification: C

3. Bicycle rusts

• Rust (iron oxide) is a new substance (oxidation).
• Classification: C

4. Solid crushed to powder

• Only shape changes (same substance).
• Classification: P

5. Two substances mixed, light produced

• Light production (e.g., combustion) means a chemical reaction.
• Classification: C

6. Ice melts and reacts with sodium

• Reaction with sodium (new substance formed) is chemical.
• Classification: C

7. Mixing salt and pepper

• No reaction, just mixing (same substances).
• Classification: P

8. Chocolate syrup dissolved in milk

• Dissolving (no new substance, physical mixing).
• Classification: P

9. Marshmallow toasted

• Toasting causes burning (new substances, chemical change).
• Classification: C

10. Marshmallow cut in half

• Only shape changes (same substance).
• Classification: P

Final Answers (row-wise):

1. P
2. C
3. C
4. P
5. C
6. C
7. P
8. P
9. C
10. P