Physical and Chemical Changes

Front

What is a chemical change?

Back

A process where substances combine or break apart to form new substances, often accompanied by energy changes.

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What is a physical change?

Back

A change that affects one or more physical properties of a substance without altering its chemical composition.

Front

What is an example of a chemical change?

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Burning wood, which produces ash, smoke, and gases.

Front

What is an example of a physical change?

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Melting ice into water, which retains the same chemical composition.

Front

What are indicators of a chemical change?

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Color change, temperature change, gas production, and formation of a precipitate.

Front

What happens during a reaction between hydrochloric acid and potassium hydroxide?

Back

They react to form potassium chloride (a salt), water, and heat, indicating a chemical change.

Front

What is rusting?

Back

A chemical change where iron reacts with oxygen and moisture to form iron oxide (rust).

Front

What is the role of energy in chemical changes?

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Energy is either absorbed or released during a chemical change, affecting the temperature and state of the substances involved.

Front

What is the difference between endothermic and exothermic reactions?

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Endothermic reactions absorb energy, while exothermic reactions release energy.

Front

What is an example of a physical change involving a state change?

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Water boiling to form steam, which is a change from liquid to gas.