Physical and Chemical Changes

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What is a physical change?

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A physical change is a change that affects one or more physical properties of a substance without altering its chemical composition. Examples include melting, freezing, and dissolving.

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What is a chemical change?

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A chemical change is a change that results in the formation of new chemical substances. It involves a chemical reaction and changes the composition of the original substance. Examples include burning, rusting, and cooking.

Front

What happens to ice cream when it melts?

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Melting ice cream is an example of a physical change because the composition of the ice cream remains the same, even though its state changes from solid to liquid.

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What is an indicator of a chemical change?

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Indicators of a chemical change include unexpected temperature changes, color changes, gas production (bubbles), and the formation of precipitates.

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What does it mean if a substance dissolves in water?

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If a substance dissolves in water, it undergoes a physical change, as the substance's chemical composition remains unchanged.

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What is an example of a chemical change involving temperature?

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An example of a chemical change involving temperature is when vinegar and baking soda are mixed, producing carbon dioxide gas and causing a temperature change.

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What happens to a copper penny over time?

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A copper penny turning greenish over time is an example of a chemical change due to oxidation, which alters its chemical composition.

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What is NOT an indicator of a chemical change?

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Bubbles and steam rising from a pot of boiling salt water is NOT an indicator of a chemical change; it is a physical change.

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What is wood burning an example of?

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Wood burning is an example of a chemical change because it produces new substances (ash, smoke) and releases energy.

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What is the difference between a physical and chemical change?

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A physical change does not alter the chemical composition of a substance, while a chemical change results in the formation of new substances.