Final answer:
The difference between physical and chemical changes is that a physical change does not alter the chemical composition of a substance, while a chemical change results in new substances with different properties.
Step-by-step explanation:
The difference between a physical change and a chemical change is how the composition of the substance is affected. In a physical change, the appearance, state, or shape of a substance may change, but its chemical composition remains the same. Examples include melting, freezing, and dissolving. In contrast, a chemical change involves the breaking and forming of bonds between atoms, resulting in new substances with different properties. Indicators of a chemical change include a color change, temperature change, light emission, gas production, and the formation of a precipitate.
Given the options provided, the correct answer is B: A physical change is a change from one state of matter to another; a chemical change results in a new substance formed. This option accurately captures the essence of physical and chemical changes in substances.