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 can be identified by changes such as color change, gas production, or temperature change.

Front

What is an example of a chemical change?

Back

Lighting a match is an example of a chemical change because it produces new substances (ash, smoke) through combustion.

Front

What happens to butter when it melts? Is it a physical or chemical change?

Back

When butter melts, it undergoes a physical change because it changes from solid to liquid without forming a new substance.

Front

What are some signs that a chemical change has occurred?

Back

Signs of a chemical change include color change, gas production (bubbles), formation of a precipitate, and temperature change.

Front

True or False: All changes in color indicate a chemical change.

Back

False. Changes in color can occur in both physical and chemical changes.

Front

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

Back

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

Front

What is an example of a physical change?

Back

Cutting a piece of paper is an example of a physical change because the paper remains paper, just in smaller pieces.

Front

What occurs when vinegar and baking soda are mixed?

Back

When vinegar and baking soda are mixed, a chemical change occurs, producing carbon dioxide gas (bubbles) and a new substance.

Front

What is meant by 'new substance' in the context of chemical changes?

Back

A new substance refers to a material that has different properties and composition from the original substances after a chemical reaction.