Understanding Water Drops: Cohesion and Adhesion

The video explains why water drops form beads on some surfaces and spread out on others. This behavior is due to cohesion, the attraction between water molecules, and adhesion, the attraction between water molecules and other surfaces. When adhesion is stronger, water spreads out; when cohesion is stronger, water forms beads.

What is the initial observation about water drops on different surfaces?

• They always form puddles.

• They remain unchanged on all surfaces.

• They look like beads on leaves but spread on tables.

• They evaporate quickly.

What force is responsible for water molecules sticking together in a drop?

• Friction

• Cohesion

• Adhesion

• Gravity

How does adhesion affect water drops on surfaces?

• It influences their spread on surfaces.

• It makes them evaporate.

• It causes them to bounce.

• It changes their color.

What happens when adhesion is stronger than cohesion?

• Water drops form beads.

• Water drops change color.

• Water drops spread out.

• Water drops evaporate.

Why do water drops form beads on waxy leaves?

• Because of low humidity.

• Because of high temperature.

• Because cohesion is stronger than adhesion.

• Because adhesion is stronger than cohesion.