Physical Change or Chemical Change?

Front

What is a physical change?

Back

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.

Front

What is a chemical change?

Back

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 original substance. Examples include rusting, burning, and digestion.

Front

What are some indicators of a chemical change?

Back

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

Front

What happens to the molecules during a physical change?

Back

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

Front

What happens to the molecules during a chemical change?

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

Front

Is dissolving sugar in water a physical or chemical change?

Back

Dissolving sugar in water is a physical change because the sugar can be recovered by evaporating the water, and its chemical composition remains unchanged.

Front

Is burning wood a physical or chemical change?

Back

Burning wood is a chemical change because it produces new substances such as ash, carbon dioxide, and water vapor.

Front

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.

Front

Can a physical change be reversed?

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Many physical changes can be reversed, such as freezing and melting, but some may not be easily reversible, like breaking a glass.

Front

Can a chemical change be reversed?

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Most chemical changes are not easily reversible. For example, burning paper cannot be reversed to get the original paper back.