Problem Overview:
The task is to classify each of the given scenarios as either a
physical change (P) or a
chemical change (C).
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Physical Change: A change in which the substance's physical properties (e.g., shape, size, state) are altered, but its chemical composition remains the same.
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Chemical Change: A change in which the substance undergoes a chemical reaction, resulting in the formation of new substances with different chemical properties.
Solution:
Let's analyze each scenario step by step:
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#### 1.
Glass Breaking
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Analysis: When glass breaks, its shape changes, but the material itself (silica and other components) remains the same.
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Classification: Physical Change
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Answer: P
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#### 2.
Hammering wood together to build a playhouse
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Analysis: Hammering wood involves changing the shape and arrangement of the wood pieces, but the wood itself does not undergo any chemical transformation.
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Classification: Physical Change
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Answer: P
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#### 3.
A rusting bicycle
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Analysis: Rusting is a chemical reaction where iron reacts with oxygen and water to form iron oxide (rust). This is a new substance with different properties.
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Classification: Chemical Change
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Answer: C
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#### 4.
Melting butter for popcorn
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Analysis: Melting butter involves a change in the state of matter from solid to liquid, but the chemical composition of the butter remains unchanged.
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Classification: Physical Change
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Answer: P
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#### 5.
Separating sand from gravel
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Analysis: Separating sand from gravel involves physically sorting the materials based on size or density, without altering their chemical composition.
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Classification: Physical Change
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Answer: P
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#### 6.
Corroding metal
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Analysis: Corrosion is a chemical process where metal reacts with substances in its environment (e.g., oxygen, water) to form new compounds, such as rust or tarnish.
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Classification: Chemical Change
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Answer: C
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#### 7.
Fireworks exploding
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Analysis: Fireworks involve chemical reactions where chemicals burn and react to produce light, sound, and color. New substances are formed during this process.
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Classification: Chemical Change
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Answer: C
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#### 8.
A tree burns to form ashes
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Analysis: Burning a tree is a chemical reaction where the organic matter in the tree reacts with oxygen to produce carbon dioxide, water vapor, and ash. New substances are formed.
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Classification: Chemical Change
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Answer: C
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#### 9.
Water freezes to form ice
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Analysis: Freezing water involves a change in the state of matter from liquid to solid, but the chemical composition of water (H₂O) remains the same.
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Classification: Physical Change
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Answer: P
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#### 10.
Squeezing oranges to make orange juice
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Analysis: Squeezing oranges extracts the juice without altering the chemical composition of the fruit. No new substances are formed.
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Classification: Physical Change
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Answer: P
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Final Answers:
1. P
2. P
3. C
4. P
5. P
6. C
7. C
8. C
9. P
10. P
Boxed Final Answer:
\[
\boxed{P, P, C, P, P, C, C, C, P, P}
\]
Parent Tip: Review the logic above to help your child master the concept of physical and chemical changes worksheet answers.
