Question

define the following terms:

1. cohesion
2. adhesion
3. capillary action
4. surface tension

Explanation:

1. Cohesion: It is the intermolecular force that causes a liquid to resist separation. For example, water molecules stick to each other due to hydrogen bonding.
2. Adhesion: This is the attraction between molecules of different substances. An example is water adhering to the walls of a glass container.
3. Capillary Action: It is the ability of a liquid to flow in narrow spaces without the assistance of, or even in opposition to, external forces like gravity. This occurs due to the combination of adhesion and cohesion. For instance, water rising in a narrow tube.
4. Surface Tension: It is the property of the surface of a liquid that allows it to resist an external force. It is caused by the cohesive forces between liquid molecules. A classic example is a water droplet maintaining a spherical shape.

Answer:

1. Cohesion: Intermolecular force causing liquid to resist separation.
2. Adhesion: Attraction between molecules of different substances.
3. Capillary Action: Liquid flowing in narrow spaces due to adhesion and cohesion.
4. Surface Tension: Liquid surface resisting external force due to cohesive forces.