Which list includes only physical properties?
A. density, reactivity, and conductivity
B. boiling point, conductivity, and color
C. color, odor, and flammability
D. flammability, reactivity, and ductility
The Correct Answer and Explanation is:
The correct answer is B. boiling point, conductivity, and color.
Explanation:
Physical properties are characteristics of a substance that can be observed or measured without changing the chemical identity of the substance. These properties can provide valuable information about the nature and behavior of materials. To understand why option B is correct, let’s examine each of the provided options in detail:
- Option A: Density, reactivity, and conductivity.
- Density is indeed a physical property, as it can be measured (mass per unit volume) without altering the substance. However, reactivity refers to how a substance interacts with others to form new substances, which is a chemical property. Conductivity (the ability to conduct electricity) is a physical property, but since reactivity is included, this option is not correct.
- Option B: Boiling point, conductivity, and color.
- All three of these are physical properties. The boiling point is the temperature at which a substance changes from liquid to gas, a physical change. Conductivity measures how well a substance allows electricity to flow through it, and color is an observable characteristic of the substance. None of these properties alter the chemical identity of the substance, making this option the correct choice.
- Option C: Color, odor, and flammability.
- Color and odor are physical properties, but flammability is a chemical property, as it describes how a substance reacts with oxygen to produce fire.
- Option D: Flammability, reactivity, and ductility.
- Similar to option C, flammability and reactivity are both chemical properties. Ductility, which is the ability of a material to be stretched into a wire, is a physical property, but since the other two are chemical, this option is also incorrect.
In conclusion, option B includes only physical properties, making it the correct answer. Understanding the distinction between physical and chemical properties is essential in fields such as chemistry and materials science, as it helps in the identification and utilization of substances based on their characteristics.