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 changes in shape, size, or state of matter.

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 the breaking and forming of bonds.

Front

Can physical changes be reversed?

Back

Yes, physical changes can often be reversed. For example, ice melting into water can be frozen back into ice.

Front

Can chemical changes be reversed?

Back

Chemical changes are usually not easily reversible. For example, burning wood creates ash and gases, which cannot be turned back into wood.

Front

What is an example of a physical change that is not a change of state?

Back

An example of a physical change that is not a change of state is cutting paper.

Front

What evidence indicates a chemical change has occurred?

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Evidence of a chemical change includes the production of gas, a change in color, the formation of a precipitate, or a change in temperature.

Front

What is the difference between a physical change and a chemical change?

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The main difference is that a physical change does not alter the chemical composition of a substance, while a chemical change results in the formation of new substances.

Front

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.

Front

What happens to the molecules during a chemical change?

Back

During a chemical change, the bonds between molecules are broken and new bonds are formed, resulting in new substances.

Front

What is an example of a chemical change?

Back

An example of a chemical change is the reaction of vinegar and baking soda, which produces carbon dioxide gas.