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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 shredding paper, melting ice, and dissolving sugar in water.

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What is a chemical change?

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A chemical change occurs when a substance transforms into a different substance with a new chemical composition. Indicators include color change, gas production, and energy emission.

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What is the general reaction scheme for a double replacement reaction?

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The general reaction scheme for a double replacement reaction is: AB + CD → AD + CB.

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What is the general reaction scheme for a single replacement reaction?

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The general reaction scheme for a single replacement reaction is: A + BC → AC + B.

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What is combustion?

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Combustion is a chemical reaction that occurs when a substance reacts with oxygen, producing heat and light. It typically involves hydrocarbons reacting with oxygen to produce carbon dioxide and water.

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What are the signs of a chemical reaction?

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Signs of a chemical reaction include color change, gas production, change in odor, and emission of energy (heat or light).

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What is a combination reaction?

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A combination reaction is a type of chemical reaction where two or more substances combine to form a single product. The general form is A + B → AB.

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What is a decomposition reaction?

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A decomposition reaction is a type of chemical reaction where a single compound breaks down into two or more simpler substances. The general form is AB → A + B.

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

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A physical property can be observed without changing the substance's chemical identity (e.g., color, melting point), while a chemical property describes a substance's ability to undergo a specific chemical change (e.g., flammability, reactivity).

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What is an example of a physical change?

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An example of a physical change is melting ice. The ice changes from solid to liquid, but its chemical composition (H2O) remains the same.