Physical 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 the breaking and forming of bonds. Examples include burning, rusting, and cooking.

Front

What happens to the chemical composition of a substance during a physical change?

Back

The chemical composition of a substance remains the same during a physical change.

Front

What happens to the chemical composition of a substance during a chemical change?

Back

The chemical composition of a substance changes during a chemical change, resulting in the formation of new substances.

Front

Give an example of a physical change and explain why it is classified as such.

Back

Melting ice cream is an example of a physical change because it changes from solid to liquid without altering its chemical composition.

Front

Give an example of a chemical change and explain why it is classified as such.

Back

Burnt toast is an example of a chemical change because the bread undergoes a chemical reaction that produces new substances, such as carbon.

Front

What is the significance of energy changes in chemical changes?

Back

Energy changes, such as heat absorption or release, are often associated with chemical changes and indicate that a reaction is occurring.

Front

What is an indicator of a chemical change?

Back

Indicators of a chemical change include color change, gas production, formation of a precipitate, and temperature change.

Front

How does dyeing hair represent a chemical change?

Back

Dyeing hair represents a chemical change because the dye interacts with the hair's chemical structure, resulting in a permanent color change.

Front

What role do reactants and products play in a chemical change?

Back

Reactants are the starting substances that undergo a chemical change, while products are the new substances formed as a result of the reaction.