8.5E - 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 changes in state (like melting or freezing), shape, or size.

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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 rusting, burning, or cooking.

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What is an example of a physical change?

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Getting a haircut is an example of a physical change because it alters the appearance of hair without changing its chemical structure.

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What is an example of a chemical change?

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Burning sugar is an example of a chemical change because it produces new substances (like carbon dioxide and ash) and gives off heat and odor.

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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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What happens when baking soda and vinegar are mixed?

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When baking soda and vinegar are mixed, a chemical change occurs, producing carbon dioxide gas, which can be observed as bubbles.

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What is rusting?

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Rusting is a chemical change that occurs when iron reacts with oxygen and moisture in the air, forming iron oxide (rust).

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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 the formation of new substances.

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What is an example of a chemical change in everyday life?

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An example of a chemical change in everyday life is cooking food, where ingredients undergo chemical reactions to create new flavors and textures.

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What does it mean when a substance undergoes a color change?

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A color change often indicates a chemical change, as it suggests that new substances with different properties have formed.