Chemical vs Physical 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 changes in state (like melting or freezing), shape, or size.

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 rearrangement of atoms and can be identified by signs such as color change, gas production, or heat release.

Front

Give an example of a physical change.

Back

Freezing water into ice is an example of a physical change.

Front

Give an example of a chemical change.

Back

The rusting of iron is an example of a chemical change.

Front

What are some signs of a chemical change?

Back

Signs of a chemical change include a change in color, production of gas, formation of a precipitate, and release or absorption of heat.

Front

Which of the following is not a sign of a chemical change?

Back

Reversibility is not a sign of a chemical change.

Front

Why can some physical changes be irreversible?

Back

Some physical changes can be irreversible because the original form may be too damaged or altered, making it impossible to return to its original state.

Front

What determines if a change is reversible or irreversible in physical changes?

Back

Whether a new substance is formed determines if a change is reversible or irreversible.

Front

What happens to the chemical composition during a physical change?

Back

The chemical composition remains unchanged during a physical change.

Front

What happens to the chemical composition during a chemical change?

Back

The chemical composition changes during a chemical change, resulting in new substances.