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 includes processes like burning, rusting, and digestion.

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What is an example of a chemical change?

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An example of a chemical change is the digestion of food in the stomach, where food is broken down into new substances.

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What is an example of a physical change?

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An example of a physical change is melting butter for popcorn, where the butter changes state from solid to liquid but remains butter.

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What are signs that a chemical change has occurred?

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Signs of a chemical change include the formation of a gas, a change in color, the production of heat or light, and the formation of a precipitate.

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Is hammering wood together a physical or chemical change?

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Hammering wood together is a physical change because it alters the shape of the wood without changing its chemical composition.

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What happens during a chemical reaction?

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During a chemical reaction, reactants are transformed into products, resulting in the formation of new substances with different properties.

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

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

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Can a chemical change be reversed?

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Some chemical changes can be reversed through other chemical reactions, but many cannot be easily reversed.

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What is an example of a physical change that can be reversed?

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An example of a reversible physical change is freezing water to make ice, which can be melted back into water.