Which of the following is not a defining characteristic of water?
A. Low specific heat capacity
B. Polarity
C. Cohesion
D. Surface tension
The Correct Answer and Explanation is:
The correct answer is A. Low specific heat capacity.
Water has a high specific heat capacity, not a low one. This means it can absorb a large amount of heat before its temperature increases significantly. This unique property of water plays a critical role in regulating temperature in the environment and living organisms. For instance, oceans and lakes absorb and release heat slowly, helping to moderate global temperatures and create a stable climate.
Let’s look at why each of the other choices (B, C, and D) are true defining characteristics of water:
- Polarity: Water molecules are polar, meaning they have a partial positive charge on one side (the hydrogen atoms) and a partial negative charge on the other side (the oxygen atom). This polarity allows water molecules to form hydrogen bonds with each other, which is crucial for many of water’s properties, such as dissolving ionic compounds and other polar substances, making it an excellent solvent.
- Cohesion: Water molecules exhibit cohesion, meaning they are attracted to each other and “stick together.” This property is due to hydrogen bonding, which creates a network of water molecules. Cohesion allows for surface tension and supports processes like the upward movement of water in plants through capillary action.
- Surface Tension: Surface tension is a result of the cohesive forces between water molecules at the surface of a liquid. Since water molecules are attracted to each other, they form a “film” at the surface, allowing small objects, such as insects, to “walk” on water. This surface tension is particularly high in water due to its strong hydrogen bonds.
In summary, water’s high specific heat capacity, polarity, cohesion, and surface tension are key factors in its behavior in biological and environmental contexts. Answer choice A is incorrect because it states the opposite of one of water’s defining characteristics.