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. Examples include changes in size, shape, or state of matter.

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.

Rust is NOT an example of a physical change; it is a chemical change.

In a physical change, the matter begins and ends as the same substance.

In a chemical change, the matter transforms into one or more new substances.

Dissolving salt in water is a physical change.

Examples of physical changes include crumpling paper, sharpening a pencil, and freezing water.

Examples of chemical changes include rusting iron, burning wood, and baking a cake.

A physical change does not change the chemical composition of a substance, while a chemical change results in new substances being formed.

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