Physical and Chemical 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 melting ice or tearing paper.

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What is a chemical change?

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A chemical change occurs when substances combine or break apart to form new substances with different properties. Examples include burning wood or cooking food.

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What is an example of a chemical change?

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Cooking eggs for breakfast is an example of a chemical change because the heat causes the proteins in the eggs to change structure.

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What happens during burning?

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During burning, a substance reacts with oxygen to produce heat and light, resulting in new substances, such as ash and gases.

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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, which is commonly known as rust.

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What are signs of a chemical change?

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Signs of a chemical change include a change in color, production of gas, formation of a precipitate, and change in temperature.

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Why should steel wool be stored in a dry place?

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Steel wool should be stored in a dry place to prevent rusting, which occurs when it is exposed to moisture.

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What is an example of a physical change?

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Bending a piece of metal is an example of a physical change because the metal's shape changes, but its chemical composition remains the same.

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What does a change in color indicate?

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A change in color can indicate a chemical change, as it often signifies that new substances are being formed.

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What is the difference between physical and chemical changes?

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Physical changes do not alter the chemical composition of a substance, while chemical changes result in the formation of new substances.