The evidence that a chemical change has happened in the scenario described includes:
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Color change - The formation of a red powdery substance indicates a change in color, which can signify a chemical change.
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Formation of a precipitate - The settling of the red powdery substance at the bottom of the container is evidence of a precipitate forming, indicating a chemical reaction has occurred.
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Generation of a new gas - The formation of bubbles that rise to the top of the container suggests that a gas is being produced, which is also indicative of a chemical change.
While a new odor produced and change in temperature can also be evidence of a chemical change, they are not mentioned as occurring in your specific scenario. Based on the information provided, the relevant evidence for a chemical change is primarily the color change, formation of a precipitate, and generation of a new gas.