Question

1. which of the following is not a phase change?

a) melting

b) burning

c) freezing

d) boiling

Explanation:

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<reasoning>

Define phase changes vs. chemical changes

Phase changes (melting, freezing, boiling) are physical transitions between states of matter (solid, liquid, gas) without altering chemical composition.

Analyze the given options

• Melting: physical transition from solid to liquid.
• Burning: chemical reaction (combustion) that alters chemical composition.
• Freezing: physical transition from liquid to solid.
• Boiling: physical transition from liquid to gas.

Identify the non-phase change

Burning is a chemical change, not a physical phase change.
</reasoning>

<answer>
<mcq-option>A) melting</mcq-option>
<mcq-correct>B) burning</mcq-correct>
<mcq-option>C) freezing</mcq-option>
<mcq-option>D) boiling</mcq-option>
</answer>

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Answer:

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<reasoning>

Define phase changes vs. chemical changes

Phase changes (melting, freezing, boiling) are physical transitions between states of matter (solid, liquid, gas) without altering chemical composition.

Analyze the given options

• Melting: physical transition from solid to liquid.
• Burning: chemical reaction (combustion) that alters chemical composition.
• Freezing: physical transition from liquid to solid.
• Boiling: physical transition from liquid to gas.

Identify the non-phase change

Burning is a chemical change, not a physical phase change.
</reasoning>

<answer>
<mcq-option>A) melting</mcq-option>
<mcq-correct>B) burning</mcq-correct>
<mcq-option>C) freezing</mcq-option>
<mcq-option>D) boiling</mcq-option>
</answer>

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