Question

1. which of the following is not evidence of a chemical reaction?

a) bubbles given off

b) precipitate forming

c) light/heat

d) change in shape

Explanation:

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<reasoning>

Identify indicators of chemical reactions

• Bubbles given off (gas production) indicates a chemical change.
• Precipitate forming (insoluble solid formation) indicates a chemical change.
• Light/heat (energy release or absorption) indicates a chemical change.

Identify physical changes

• Change in shape is a physical alteration of the substance's form, not its chemical identity.

</reasoning>

<answer>
<mcq-option>A) bubbles given off</mcq-option>
<mcq-option>B) precipitate forming</mcq-option>
<mcq-option>C) light/heat</mcq-option>
<mcq-correct>D) change in shape</mcq-correct>
</answer>

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Answer:

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<reasoning>

Identify indicators of chemical reactions

• Bubbles given off (gas production) indicates a chemical change.
• Precipitate forming (insoluble solid formation) indicates a chemical change.
• Light/heat (energy release or absorption) indicates a chemical change.

Identify physical changes

• Change in shape is a physical alteration of the substance's form, not its chemical identity.

</reasoning>

<answer>
<mcq-option>A) bubbles given off</mcq-option>
<mcq-option>B) precipitate forming</mcq-option>
<mcq-option>C) light/heat</mcq-option>
<mcq-correct>D) change in shape</mcq-correct>
</answer>

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