Understanding Chemical Reactions

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What is a chemical reaction?

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A process where substances (reactants) undergo a transformation to form new substances (products) with different properties.

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What indicates that a chemical reaction has occurred?

Back

A change in the arrangement of atoms, which can be observed through changes in temperature, color, odor, or the formation of gas or precipitate.

Front

What are reactants in a chemical reaction?

Back

The starting substances that undergo change during a chemical reaction.

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What are products in a chemical reaction?

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The new substances formed as a result of a chemical reaction.

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What is the law of conservation of mass?

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In a chemical reaction, mass is neither created nor destroyed; the total mass of reactants equals the total mass of products.

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What is an example of a physical change?

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Melting ice into water, where the substance remains the same (H2O) but changes state.

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What is an example of a chemical change?

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Burning wood, which transforms it into ash, smoke, and gases, creating new substances.

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What is an exothermic reaction?

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A chemical reaction that releases energy, usually in the form of heat, to the surroundings.

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What is an endothermic reaction?

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A chemical reaction that absorbs energy from the surroundings, resulting in a decrease in temperature.

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What is a catalyst?

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A substance that speeds up a chemical reaction without being consumed in the process.