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 processes like burning, rusting, and baking.

Front

What happens to a chocolate bar when it melts?

Back

Melting a chocolate bar is a physical change because it changes from solid to liquid without changing its chemical structure.

Front

What causes iron to change from shiny to rusty?

Back

The change from shiny to rusty iron is caused by a chemical reaction with oxygen and moisture in the air, resulting in rust.

Front

What is a precipitate?

Back

A precipitate is a solid that forms and settles out of a liquid mixture during a chemical reaction.

Front

Is dissolving Gatorade powder in water a physical or chemical change?

Back

Dissolving Gatorade powder in water is a physical change because the powder retains its chemical identity.

Front

What is an example of a chemical change in cooking?

Back

Baking cupcakes is an example of a chemical change because the ingredients undergo a chemical reaction to form new substances.

Front

What are indicators of a chemical change?

Back

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

Front

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

Back

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

Front

Can physical changes be reversed?

Back

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