Definition of Adhesion and Cohesion
As for the definitions of Adhesion and Cohesion, adhesion is the tendency of two or more different molecules to link together, whereas cohesion is the force of attraction between the same molecules.
The adhesion forces may be one consequence of the electrostatic forces exerted on various substances. The cohesive forces are related to Van der Waals forces and hydrogen bonding, which allow liquids like water to resist separation. When water is spilled over a glass surface, both adhesive and cohesive forces act on the water’s surface. A strong cohesive force is responsible for the creation of water droplets on the water’s surface, whereas a strong adhesive force causes the liquid to spread across the surface.
Both adhesion and cohesion forces have differing strengths. For instance, if the cohesion forces between water molecules are larger than their adhesion forces, the individual molecules will attract one another, resulting in sedimentation. If the adhesion forces of the water’s surface are greater than the cohesion forces of its molecules, the water tends to scatter.
There are a variety of natural phenomena that explain the numerous things we observe in our daily lives. Despite this, we sometimes neglect to pay attention to the tiny things that sustain life on earth. The forces of adhesion and cohesion are one of two phenomena. Although they share a similar pronunciation, they are distinct terms. The link between adhesion and cohesion is one of the key physical properties of water that is described by surface tension.
Differences Between Adhesion and Cohesion
| Sr.no | Adhesion | Cohesion |
| 1. | Adhesion occurs between molecules or substances that are different. | This force is known as the cohesion force when two identical substances or molecules encounter the force of attraction. |
| 2. | Generally, adhesion is the attractive force between water molecules and the walls of xylem vessels. | The cohesion force between water molecules is not restricted. |
| 3. | Adhesion results in capillary action and meniscus (the curved surface generated by any liquid in a cylinder). | Surface tension, meniscus, and capillary action are cohesion’s effects. |
| 4. | Electrostatic or mechanical forces between two types of dissimilar material produce adhesion. | Hydrogen bonding and Van der Waals forces cause cohesion. |
| 5. | Strong adhesion causes the liquid to distribute evenly throughout the surface. | On any surface, a strong force of cohesion creates water droplets |
Frequently Asked Questions – FAQs
Q.1 What is cohesion and its example?
When two identical substances or molecules encounter the force of attraction, the resulting force is referred to as cohesion force. Water demonstrates cohesiveness. Each molecule of water makes hydrogen bonds with its neighbors.
Q.2 What is adhesion and its example?
When two dissimilar substances or molecules encounter the force of attraction, this force is referred to as the adhesion force. Water drops on the leaves and flowers’ surfaces.
Q.3 What is the difference between cohesion and adhesion?
The distinction between adhesion and cohesion is that cohesion refers to the attraction between identical molecules, whereas adhesion refers to the attraction between diverse molecules.
Q.4 Why is cohesion important?
Cohesion permits the formation of surface tension, which forces the liquid’s surface to contract to the lowest feasible area. It helps plants absorb water through their roots.
