Which of the following is a unique characteristic of water resulting from its cohesive and adhesive properties?

• A. Water cannot move upward in plant stems due to lack of adhesion.
• B. Water evaporates instantly at room temperature because of weak hydrogen bonds.
• C. Water molecules repel each other, preventing surface tension.
• D. Water forms droplets on a waxed surface due to cohesion.

Answer: (D)

Verified step by step guidance

1. Understand the key terms in the question: Cohesion refers to the attraction between water molecules due to hydrogen bonding, while adhesion refers to the attraction between water molecules and other surfaces.
2. Analyze the options provided: The first option states that water cannot move upward in plant stems due to lack of adhesion. This is incorrect because adhesion helps water stick to the walls of plant vessels, enabling capillary action.
3. Evaluate the second option: It claims that water evaporates instantly at room temperature due to weak hydrogen bonds. This is incorrect because water's hydrogen bonds are relatively strong, giving it a high heat of vaporization and preventing instant evaporation.
4. Examine the third option: It states that water molecules repel each other, preventing surface tension. This is incorrect because water molecules attract each other through hydrogen bonding, creating surface tension.
5. Confirm the correct answer: The fourth option states that water forms droplets on a waxed surface due to cohesion. This is correct because cohesion causes water molecules to stick together, forming droplets even on non-polar surfaces like wax.