Question
An experiment was performed in which a crystalline substance was added to a beaker filled with a liquid at room temperature. The observations made during the experiment are listed below. All of the observations are evidence that a chemical change occurred EXCEPT -
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bubbles formed in the water.
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the bottom of the beaker felt warm to the touch.
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a precipitate formed.
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the crystals dissolved.
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bubbles formed in the water.
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the bottom of the beaker felt warm to the touch.
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a precipitate formed.
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the crystals dissolved.
Answers
GPT-4o mini
In the context of the experiment described, a chemical change is typically characterized by a reaction that results in the formation of new substances, which can be indicated by the formation of bubbles, warmth (exothermic reaction), or precipitate. However, the observation that does not necessarily indicate a chemical change is:
**the crystals dissolved.**
Dissolving a substance in a liquid can often be a physical change rather than a chemical change, especially if the substance can be recovered by evaporating the solvent. Therefore, this observation is the exception among the list provided that suggests a chemical change occurred.
**the crystals dissolved.**
Dissolving a substance in a liquid can often be a physical change rather than a chemical change, especially if the substance can be recovered by evaporating the solvent. Therefore, this observation is the exception among the list provided that suggests a chemical change occurred.