Physical and Chemical Changes

Front

What is a physical change?

Back

A physical change is a change in which the form or appearance of a substance changes, but its chemical composition remains the same. 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 cooking.

Front

What is rusting?

Back

Rusting is a chemical change that occurs when iron reacts with oxygen and moisture in the air, forming iron oxide (rust).

Front

What happens to sugar when it dissolves in water?

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When sugar dissolves in water, it breaks down into smaller particles and spreads throughout the water, forming a solution.

Front

What is an example of a chemical reaction?

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An example of a chemical reaction is the reaction between vinegar and baking soda, which produces carbon dioxide gas.

Front

What is melting?

Back

Melting is the process of a solid turning into a liquid when it is heated. For example, ice melts into water when heated.

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What is evaporation?

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Evaporation is the process by which liquid turns into vapor or gas, usually when heated. For example, water evaporates into steam.

Front

What is condensation?

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Condensation is the process by which water vapor cools and changes back into liquid water, such as when dew forms on grass.

Front

What is the difference between a solid, liquid, and gas?

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Solids have a fixed shape and volume, liquids have a fixed volume but take the shape of their container, and gases have neither fixed shape nor volume.

Front

What is an example of a physical change?

Back

An example of a physical change is breaking a glass. The glass changes shape but remains glass.