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, freezing, and dissolving.

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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 processes like rusting, burning, and cooking.

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What is a chemical reaction?

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A chemical reaction is a process in which substances (reactants) undergo a transformation to form new substances (products). This process often involves breaking and forming chemical bonds.

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What is rust?

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Rust is a reddish-brown oxide that forms on iron or steel when it reacts with oxygen and moisture in the environment. It is an example of a chemical change.

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What are substances?

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Substances are forms of matter that have specific properties and a definite composition. Examples include water, oxygen, and gold.

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What does it mean to manipulate an object?

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To manipulate an object means to move or change its position or form. This can involve physical changes like bending, stretching, or reshaping.

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What is a mixture?

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A mixture is a combination of two or more substances that are not chemically bonded. Each substance retains its own properties. Examples include salad, air, and sand.

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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 create new substances and only alters physical properties, while a chemical change results in the formation of new substances.

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What is an example of a physical change?

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An example of a physical change is ice melting into water. The substance remains H2O, but its state changes from solid to liquid.

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What is an example of a chemical change?

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An example of a chemical change is burning wood. The wood reacts with oxygen to produce ash, smoke, and gases, creating new substances.