#117 (Q) Evidence of a Chemical Change

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What is evidence of a chemical change?

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Evidence of a chemical change includes changes in color, temperature, the production of gas, the formation of a precipitate, and the release of light or heat.

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Which example shows a chemical reaction has occurred?

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Rust forming on a hammer left outside is evidence of a chemical reaction.

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What are reactants in a chemical equation?

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Reactants are the substances that undergo a chemical change, found on the left side of a chemical equation.

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What does the formation of bubbles indicate in a chemical reaction?

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The formation of bubbles may indicate that a gas is being produced as a result of a chemical reaction.

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What is NOT evidence of a chemical reaction?

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Melting is NOT evidence of a chemical reaction; it is a physical change.

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What is a precipitate?

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A precipitate is a solid that forms from a solution during a chemical reaction.

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What does it mean if a chemical reaction produces light or heat?

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The production of light or heat indicates that a chemical reaction is occurring, often releasing energy.

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What is the significance of color change in a chemical reaction?

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A color change can indicate that a new substance has formed during a chemical reaction.

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What is the role of catalysts in chemical reactions?

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Catalysts speed up chemical reactions without being consumed in the process.

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What is the difference between a physical change and a chemical change?

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A physical change alters the form of a substance without changing its identity, while a chemical change results in the formation of new substances.