Review of 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. It involves a chemical reaction and includes changes such as burning, rusting, and digestion.

Front

What evidence might indicate a chemical change has occurred?

Back

Evidence of a chemical change may include a change in color, the production of gas (bubbles), the formation of a precipitate, or a change in temperature.

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 bonds between molecules are broken and new bonds are formed, resulting in the creation of new substances.

Front

Can a physical change be reversed?

Back

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

Front

Can a chemical change be reversed?

Back

Most chemical changes are not easily reversible, as they result in the formation of new substances.

Front

What is an example of a physical change?

Back

An example of a physical change is ice melting into water.

Front

What is an example of a chemical change?

Back

An example of a chemical change is burning wood, which produces ash and smoke.

Front

What does it mean if no observable evidence of a chemical change is detected?

Back

It may mean that only a physical change occurred.