Physical Change or Chemical Change?

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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 changes the molecular structure of the substance. Examples include burning, rusting, and digestion.

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What are some indicators of a chemical change?

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Indicators of a chemical change include color change, temperature change, gas production (bubbles), formation of a precipitate, and change in odor.

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What happens to the molecules during a physical change?

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During a physical change, the arrangement of molecules may change, but the molecules themselves remain the same. For example, ice melting into water.

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What happens to the molecules during a chemical change?

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During a chemical change, the bonds between molecules are broken and new bonds are formed, resulting in new substances. For example, when hydrogen and oxygen combine to form water.

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Is boiling water a physical or chemical change?

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Boiling water is a physical change because it changes from liquid to gas (steam) without altering its chemical composition.

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Is rusting of iron a physical or chemical change?

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Rusting of iron is a chemical change because it forms a new substance, iron oxide, through a reaction with oxygen.

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What is an example of a reversible physical change?

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An example of a reversible physical change is freezing water to make ice, which can be melted back into water.

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What is an example of an irreversible chemical change?

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An example of an irreversible chemical change is baking a cake, where the ingredients undergo a chemical reaction to form a new product.

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What is the law of conservation of mass?

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The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction; the total mass of the reactants equals the total mass of the products.