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 changes in state, shape, or size.

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 breaking and forming of bonds.

Front

Give an example of a physical change.

Back

An example of a physical change is boiling water, where water changes from liquid to gas but remains H2O.

Front

Give an example of a chemical change.

Back

An example of a chemical change is the burning of wood, which produces ash, smoke, and gases, changing the original substance.

Front

What happens to the molecules during a physical change?

Back

During a physical change, the molecules may change their arrangement or state, but their chemical structure remains the same.

Front

What happens to the molecules during a chemical change?

Back

During a chemical change, the molecules undergo a transformation that alters their chemical structure, resulting in new substances.

Front

What is rusting, and is it a physical or chemical change?

Back

Rusting is the process where iron reacts with oxygen and moisture to form iron oxide (rust). It is a chemical change.

Front

What is the difference between a reversible and irreversible change?

Back

A reversible change can be undone (e.g., melting ice), while an irreversible change cannot be easily reversed (e.g., baking a cake).

Front

What are some 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

Is dissolving sugar in water a physical or chemical change?

Back

Dissolving sugar in water is a physical change because the sugar can be recovered by evaporating the water.