What characteristic of water is described by its boiling point?

• A. Chemical property only
• B. Physical property
• C. Biological property
• D. Reactivity property

Answer: (B)

The boiling point of water is classified as a physical property because it describes a characteristic that can be observed without changing the substance's chemical structure. Physical properties involve attributes such as color, odor, density, and state of matter, which can all be measured or observed directly. The boiling point specifically indicates the temperature at which water transitions from liquid to gas, reflecting how the substance behaves under certain conditions without altering its chemical identity.

This distinction is important in understanding the types of properties that substances exhibit. Chemical properties, on the other hand, relate to how a substance interacts with other materials or changes into different substances, such as when water reacts with sodium to produce sodium hydroxide and hydrogen gas. Biological properties pertain to the characteristics of living organisms and their functions, while reactivity properties involve the tendency of a substance to undergo chemical changes during interactions with other substances. In this context, since boiling point is purely a measurement of a state change and does not involve any transformation of the water itself, it is clearly identified as a physical property.