Chemical & Physical Changes

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What is a chemical change?

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A chemical change is a process where substances combine or break apart to form new substances with different properties. Examples include rusting, burning, and digestion.

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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.

Front

What happens when bubbles form during a reaction?

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The formation of bubbles indicates a chemical change, often due to the production of gas.

Front

What is an example of a chemical change involving odor?

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Rotting fruit produces a bad smell, which is a sign of a chemical change occurring.

Front

Is rusting a chemical or physical change?

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Rusting is a chemical change because it involves the reaction of iron with oxygen to form rust.

Front

What occurs when water freezes?

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When water freezes to form ice, it undergoes a physical change, as its chemical composition remains H2O.

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What is an indicator of a chemical reaction?

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Indicators of a chemical reaction include color change, temperature change, gas production (bubbles), and the formation of a precipitate.

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Can a physical change be reversed?

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Many physical changes can be reversed, such as melting and freezing, but some may not be easily reversible.

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What is an example of a physical change?

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An example of a physical change is chopping wood; the wood's composition remains the same.

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

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