Property Changes in Chemical and Physical Reactions WRA

What defines a physical change according to the passage?

• When a substance changes into a completely new substance.

• When the form or appearance of a substance changes, but its chemical identity remains unchanged.

• When a substance reacts with oxygen to form rust.

• When a substance undergoes a change in temperature.

Which of the following is an example of a physical change according to the passage?

• Burning wood

• Rusting iron

• Melting ice

• Baking a cake

How is a chemical change characterized according to the passage?

• When a substance changes state from solid to liquid.

• When the chemical structure of a substance remains unchanged.

• When atoms rearrange themselves to form new chemical bonds, resulting in the formation of new substances.

• When a substance dissolves in water to form a solution.

Which of the following is an indicator that a chemical change has occurred?

• The substance melts.

• The substance tears into smaller pieces.

• The production of gas (bubbles).

• The substance stretches without breaking.

What do baking a cake and rusting iron have in common, based on the passage?

• Both involve dissolving substances in water.

• Both result in a change of state from solid to liquid.

• Both are examples of physical changes.

• Both are examples of chemical changes.