Unit 3 | Chemical and 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 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. Examples include rusting, burning, and mixing vinegar with baking soda.

Front

What happens to molecules when heat is added?

Back

When heat is added, molecules move faster and spread apart, which can lead to a change in state, such as from solid to liquid.

Front

What is the change from liquid to gas called?

Back

The change from liquid to gas is called evaporation, which is a type of physical change.

Front

What is an example of a physical change?

Back

Cutting a banana is an example of a physical change because it does not change the chemical composition of the banana.

Front

What is an example of a chemical change?

Back

Bananas turning brown is an example of a chemical change because it involves a change in the chemical composition of the banana.

Front

What occurs when an antacid tablet is mixed with water?

Back

When an antacid tablet is mixed with water, a chemical change occurs, producing bubbles as a new substance is formed.

Front

What does it mean when a substance absorbs heat?

Back

When a substance absorbs heat, it takes in energy, which can cause a change in state, such as ice melting into water.

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

What is an example of a mixture?

Back

A salad is an example of a mixture because it combines different ingredients without changing their individual properties.