Physical and Chemical Changes

Front

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 cutting.

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What is a chemical change?

Back

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 baking.

Front

What evidence indicates a chemical change has occurred?

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Evidence of a chemical change includes color change, gas production (bubbles), temperature change, and the formation of a precipitate.

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Can physical changes be reversed?

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Yes, physical changes can often be reversed. For example, ice can melt into water and then freeze back into ice.

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Can chemical changes be reversed?

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Chemical changes are usually not reversible by simple physical means. For example, burning wood creates ash and smoke, which cannot be turned back into wood.

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What is an example of a physical change that is not a change of state?

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An example of a physical change that is not a change of state is cutting paper.

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What is an example of a chemical change?

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An example of a chemical change is the reaction between baking soda and vinegar, which produces carbon dioxide gas.

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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 a change in chemical composition.

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What is a mixture?

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A mixture is a combination of two or more substances that retain their individual properties and can be separated by physical means.

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How can you separate a mixture of sand and water?

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You can separate a mixture of sand and water by filtering the mixture, which allows the water to pass through while trapping the sand.