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 chopping.

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 includes changes such as burning, rusting, and baking.

Front

What are some signs that a chemical change has occurred?

Back

Signs of a chemical change include temperature change, production of gas (bubbling or fizzing), color change, formation of a precipitate, and odor change.

Front

Is baking a cake a physical or chemical change?

Back

Baking a cake is a chemical change because it involves a chemical reaction that transforms the ingredients into a new substance.

Front

What happens to the molecules during a physical change?

Back

During a physical change, the molecules may change their arrangement or state (solid, liquid, gas) but their chemical structure remains the same.

Front

What happens to the molecules during a chemical change?

Back

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

Front

Give an example of a physical change.

Back

An example of a physical change is chopping wood. The wood is still wood, just in smaller pieces.

Front

Give an example of a chemical change.

Back

An example of a chemical change is rust forming on iron when it reacts with oxygen and moisture.

Front

What is an example of a sign of a chemical change?

Back

A sign of a chemical change is the production of gas, such as when vinegar and baking soda are mixed and fizzing occurs.

Front

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

Back

A physical change does not change the chemical composition of a substance, while a chemical change results in the formation of new substances.