physical and chemical changes

Front

What is a chemical change?

Back

A chemical change is a process where substances combine or break apart to form new substances with different properties.

Front

What is a physical change?

Back

A physical change is a process that alters the form or appearance of a substance but does not change its chemical composition.

Front

What is an example of a chemical change?

Back

Burning wood is an example of a chemical change.

Front

What is an example of a physical change?

Back

Breaking glass is an example of a physical change.

Front

What is a sign that a chemical reaction has occurred?

Back

Formation of a gas is a sign that a chemical reaction has occurred.

Front

Is melting a chocolate bar a physical or chemical change?

Back

Melting a chocolate bar is a physical change.

Front

Which of the following is NOT a physical change: crumpled paper, pencil sharpening, shrunken clothing, or rust?

Back

Rust is NOT a physical change; it is a chemical change.

Front

What happens to the molecules during a chemical change?

Back

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

Front

What happens to the molecules during a physical change?

Back

During a physical change, the molecules remain the same but may change in arrangement or state.

Front

Can a physical change be reversed?

Back

Many physical changes can be reversed, such as freezing and melting water.