Physical and Chemical Changes

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. Examples include burning, rusting, and cooking.

Front

Is melting ice a physical or chemical change?

Back

Melting ice is a physical change because the ice changes from solid to liquid but remains water.

Front

Is burning wood a physical or chemical change?

Back

Burning wood is a chemical change because it transforms the wood into ash, smoke, and gases.

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.

Front

What happens to the molecules during a chemical change?

Back

During a chemical change, the molecules are rearranged to form new substances with different properties.

Front

Can physical changes be reversed?

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

Front

Can chemical changes be reversed?

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Chemical changes are usually not reversible by simple physical means, as they involve the formation of new substances.

Front

What is an example of a physical change in nature?

Back

An example of a physical change in nature is the water cycle, where water evaporates, condenses, and precipitates without changing its chemical structure.

Front

What is an example of a chemical change in cooking?

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An example of a chemical change in cooking is baking a cake, where ingredients react to form a new product.