How do physical changes differ from chemical changes?

Physical changes and chemical changes are fundamental concepts in chemistry, each affecting matter in different ways. A physical change involves alterations to the form, appearance, or state of a substance without altering its chemical composition. Common examples include melting, freezing, and dissolving. During a physical change, the substance remains the same at the molecular level; only its physical attributes change.

In contrast, a chemical change transforms substances into different ones through the breaking and forming of chemical bonds. This process results in the creation of new substances with distinct properties. Examples include rusting iron and burning wood, where the original materials undergo a fundamental change in their composition.

The distinction highlighted in the correct choice encapsulates this difference succinctly: while a physical change alters the form but does not change the substance itself, a chemical change leads to the formation of new substances. This is central to understanding how matter behaves in different scenarios within chemistry.