Question

select the statement that best explains the difference between chemical and physical changes. chemical changes are a change in the physical, observable properties of a substance. most of these changes can be reversed. physical changes are a change in the atomic structure of a substance. many times, new substances are created, and most physical changes cannot be reversed. physical changes are a change in the physical, observable properties of a substance. most of these changes can be reversed. chemical changes are a change in the atomic structure of a substance. many times, new substances are created, and most chemical changes cannot be reversed.

Explanation:

Physical changes involve alterations in physical, observable properties (like shape, size, state) and are often reversible. Chemical changes involve changes in atomic structure, result in new substances, and are usually not reversible. The second option correctly assigns these characteristics to physical and chemical changes respectively.

Answer:

The second option: "Physical changes are a change in the physical, observable properties of a substance. Most of these changes can be reversed. Chemical changes are a change in the atomic structure of a substance. Many times, new substances are created, and most chemical changes cannot be reversed."