Why does water bead up on a freshly waxed car surface?

• A. Because water forms ionic bonds with the wax, resulting in beading.
• B. Because strong hydrogen bonds between water molecules cause high surface tension, preventing the water from spreading.
• C. Because the wax increases the attraction between water molecules and the car surface, causing the water to spread out.
• D. Because the wax decreases the surface tension of water, causing it to bead up.

Answer: (B)

Verified step by step guidance

1. Understand the concept of surface tension: Water molecules are attracted to each other through hydrogen bonding, which creates a 'skin' on the surface that resists spreading.
2. Recognize that wax is hydrophobic, meaning it repels water and does not form strong bonds with water molecules.
3. Because the waxed surface does not attract water, water molecules prefer to stick to each other rather than spread out on the surface.
4. This strong cohesion among water molecules due to hydrogen bonding leads to the formation of beads, minimizing the contact area with the waxed surface.
5. Therefore, the beading effect is a result of high surface tension from hydrogen bonding in water combined with the hydrophobic nature of the wax, not ionic bonding or decreased surface tension.