Question

Define cohesive force and adhesion, the force of molecules.

Answer 1

Hint: This is a direct question of defining the force of molecules. The answer to this solution becomes easy if the concept is known, as once the concept is clear then writing the answer for this question is not a big task. Also try to give an example for the definition, so that it becomes easy to define the solution and it gives more weight to the answer.

Complete solution:
Cohesive Force: - It is the action or property of similar molecules sticking together, being mutually attractive. Cohesion also allows for surface-tension, creating a solid-like state upon which lightweight or low-density materials can be placed. Water is a very good example for this, as it is strongly cohesive due to the polarity of the water molecule.

Adhesive Force: - It is the tendency of dissimilar particles or surfaces to cling/stick to one another. There are different types of adhesions like chemical adhesion, dispersive adhesion, and diffusive adhesion. Sticky Tape is a very good example of adhesion, as it can stick to any kind of surface.

Additional Information:
Intermolecular forces (IMF) are the forces which mediate interaction between atoms, including forces of attraction or repulsion which act between atoms and other types of neighboring particles, e.g. atoms or ions. Intermolecular forces are weak relative to intramolecular forces – the forces which hold a molecule together.

Note:
Always have an example mentioned in the solutions, for the question related to defining any topic as it becomes easy to explain the topic and to make others understand the definition. For defining any term, it is nice if the concept related to that term is clear, or else it will be tough to define the topic and explain it.