Which of the following is considered a physical property of matter?

• A. Flammability
• B. Density
• C. Ability to rust
• D. Reactivity with acids

Answer: (B)

Verified step by step guidance

1. Understand the difference between physical and chemical properties: Physical properties can be observed or measured without changing the substance's identity, while chemical properties describe how a substance interacts with other substances, leading to a chemical change.
2. Analyze each option: Flammability, ability to rust, and reactivity with acids all involve chemical changes because they describe how a substance reacts and transforms into new substances.
3. Recognize that density is a physical property because it is a measure of mass per unit volume (\[\text{Density} = \frac{\text{Mass}}{\text{Volume}}\]) and can be determined without altering the substance's chemical identity.
4. Conclude that among the given options, density is the physical property since it involves no chemical change and is purely a characteristic of the substance's physical state.
5. Remember that identifying physical properties involves looking for characteristics that can be observed or measured without causing a chemical reaction.