Physical and Chemical Changes

A physical change is a change that affects one or more physical properties of a substance without altering its chemical composition.

A chemical change is a change that results in the formation of new chemical substances, altering the identity of the original substance.

Examples include melting ice, boiling water, or breaking a glass.

Examples include rusting iron, burning wood, or baking a cake.

The identity of the substance remains the same during a physical change.

The identity of the substance changes during a chemical change.

Dissolving sugar in water is a physical change.

Burning paper is a chemical change.

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

Rust is a chemical compound formed when iron reacts with oxygen and moisture, indicating a chemical change.