Which of the following best describes how characteristic chemical and physical properties are alike?

• A. Both involve changes in the chemical composition of a substance.
• B. Both are used to identify and classify substances.
• C. Both can only be observed during a chemical reaction.
• D. Both are always dependent on the amount of substance present.

Answer: (B)

Verified step by step guidance

1. Understand the definitions of chemical and physical properties: Chemical properties describe a substance's ability to undergo changes that transform it into different substances, while physical properties can be observed or measured without changing the substance's chemical identity.
2. Recognize that characteristic properties are those unique to a substance and can be used to identify or classify it.
3. Note that physical properties (like melting point, density) and chemical properties (like reactivity, flammability) both serve as identifiers for substances, even though they describe different aspects.
4. Eliminate options that incorrectly state that both involve changes in chemical composition or only occur during chemical reactions, since physical properties do not require chemical changes.
5. Conclude that the best description is that both chemical and physical characteristic properties are used to identify and classify substances.