Chemical and Physical 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 cutting, melting, 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 changes such as burning, rusting, and digestion.

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What happens during a chemical change?

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During a chemical change, bonds between atoms are broken and new bonds are formed, resulting in the creation of new substances.

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What is a precipitate?

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A precipitate is a solid that forms and settles out of a liquid mixture during a chemical reaction.

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What is an example of a physical change?

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An example of a physical change is boiling water, where water changes from liquid to gas but remains H2O.

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What is an example of a chemical change?

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An example of a chemical change is burning wood, which transforms it into ash, smoke, and gases.

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What are indicators of a chemical change?

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

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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 alter the chemical composition of a substance, while a chemical change results in new substances being formed.

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What is an example of a situation where both physical and chemical changes occur?

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An example is cooking an egg: the heat causes physical changes (the egg solidifies) and chemical changes (the proteins denature and form new structures).

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What is the law of conservation of mass?

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The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction; the total mass of reactants equals the total mass of products.