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.

Front

What is a chemical change?

Back

A chemical change is a change that results in the formation of new chemical substances, involving a rearrangement of atoms.

Front

What are some signs that a chemical reaction has occurred?

Back

Signs of a chemical reaction include the formation of a gas, color change, temperature change, and the formation of a precipitate.

Front

What happens during the process of digestion in the mouth?

Back

Digestion in the mouth involves a physical change where teeth chew food, breaking it down into smaller pieces.

Front

What is evaporation?

Back

Evaporation is the process by which liquid turns into vapor, often due to heat, and is a physical change.

Front

Is melting butter a chemical or physical change?

Back

Melting butter is a physical change because it changes from solid to liquid without altering its chemical structure.

Front

What occurs when sugar dissolves in tea?

Back

When sugar dissolves in tea, it undergoes a physical change, as the sugar molecules disperse in the liquid but do not change chemically.

Front

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

Back

A physical change does not change the substance's chemical identity, while a chemical change results in the formation of new substances.

Front

Can a physical change be reversed?

Back

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

Front

What is an example of a chemical change in everyday life?

Back

An example of a chemical change is rusting of iron, where iron reacts with oxygen to form iron oxide.