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. 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. It involves a chemical reaction and the rearrangement of atoms. Examples include burning, rusting, and digestion.

Front

List two examples of physical changes.

Back

1. Ice melting into water. 2. Sugar dissolving in water.

Front

List two examples of chemical changes.

Back

1. Iron rusting when exposed to oxygen. 2. Baking a cake, where ingredients undergo a chemical reaction.

Front

What are indicators of a chemical change?

Back

Indicators of a chemical change include color change, temperature change, gas production, and the formation of a precipitate.

Front

What happens to the mass of substances during a physical change?

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The mass of substances remains the same during a physical change, as no new substances are formed.

Front

What happens to the mass of substances during a chemical change?

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The mass of substances is conserved during a chemical change, meaning the total mass of reactants equals the total mass of products.

Front

What is an example of a reversible physical change?

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An example of a reversible physical change is the melting and freezing of water.

Front

What is an example of an irreversible chemical change?

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An example of an irreversible chemical change is the burning of wood, which produces ash and gases.

Front

How can you tell if a chemical change has occurred?

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You can tell if a chemical change has occurred by observing changes such as color change, temperature change, gas production, or the formation of a solid.