Unit 5 review (chemical reactions)

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What is a physical change?

Back

A physical change is a change that affects one or more physical properties of a substance without altering its chemical composition. Examples include melting ice or mixing lemonade powder with water.

Front

What is a chemical change?

Back

A chemical change is a change that results in the formation of new chemical substances. Examples include rusting of metal and burning wood.

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What is the Law of Conservation of Matter?

Back

The Law of Conservation of Matter states that matter cannot be created or destroyed in a chemical reaction. The mass of the reactants equals the mass of the products.

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What is an exothermic reaction?

Back

An exothermic reaction is a chemical reaction that releases energy in the form of heat or light. Example: combustion of fuels.

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What is an endothermic reaction?

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An endothermic reaction is a chemical reaction that absorbs energy from its surroundings, usually in the form of heat. Example: photosynthesis.

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What happens to a copper penny over time?

Back

A copper penny can undergo a chemical change, turning greenish due to the formation of copper carbonate when it reacts with moisture and carbon dioxide in the air.

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

Back

A physical change alters the form or appearance of a substance without changing its chemical composition, while a chemical change results in the formation of new substances.

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What is corrosion?

Back

Corrosion is a chemical change that occurs when metals react with oxygen and moisture in the environment, leading to deterioration. Example: rusting of iron.

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What is a reactant?

Back

A reactant is a substance that undergoes a chemical change in a reaction. They are found on the left side of a chemical equation.

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What is a product in a chemical reaction?

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A product is a substance that is formed as a result of a chemical reaction. They are found on the right side of a chemical equation.