Physical & 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 chopping wood, melting ice, and boiling water.

Front

What is a chemical change?

Back

A chemical change is a change that results in the formation of new chemical substances. Examples include burning wood, rusting iron, and baking a cake.

Front

Can physical changes be easily reversed?

Back

Yes, physical changes can often be easily reversed. For example, melting ice can be refrozen into water.

Front

Can chemical changes be easily reversed?

Back

No, chemical changes are usually not easily reversible. For example, once a cake is baked, it cannot be turned back into its original ingredients.

Front

What happens to the properties of a substance during a physical change?

Back

The properties of a substance may change, but its chemical structure remains the same.

Front

What happens to the properties of a substance during a chemical change?

Back

The properties of a substance change, and new substances with different chemical structures are formed.

Front

Give an example of a physical change.

Back

Chopping down a tree is a physical change because it alters the shape and size of the tree but does not change its chemical composition.

Front

Give an example of a chemical change.

Back

Burning a candle is a chemical change because the wax reacts with oxygen to produce heat, light, and new substances.

Front

What is an indicator of a chemical change?

Back

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

Front

Is boiling water a physical or chemical change?

Back

Boiling water is a physical change because it changes from liquid to gas without altering its chemical composition.