Changes in Matter

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

Which of the following is NOT a physical change?

Back

A gas forming is NOT a physical change; it indicates a chemical change.

Front

What is an endothermic reaction?

Back

An endothermic reaction is a chemical reaction that absorbs energy from its surroundings, usually in the form of heat.

Front

What is an exothermic reaction?

Back

An exothermic reaction is a chemical reaction that releases energy to its surroundings, usually in the form of heat.

Front

What is temperature?

Back

Temperature is a measure of the average energy of random motion of particles in a substance.

Front

What is thermal energy?

Back

Thermal energy is the total energy of all the particles in an object, which is related to its temperature.

Front

What happens to the energy during a physical change?

Back

During a physical change, the energy may change forms (like heat energy during melting) but the substance's chemical identity remains the same.

Front

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

Back

A physical change alters the form or appearance of a substance without changing its chemical composition, 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 physical change?

Back

Examples of physical changes include tearing paper, melting ice, and dissolving sugar in water.