The force of attraction between molecules of the same substance is

The force of attraction between molecules of the same substance is called cohesion.

To understand this simply:

Cohesion refers to the attractive forces acting between similar molecules. For example, water molecules attract each other due to hydrogen bonding, which is a strong intermolecular force.

Let's break down some important concepts:

• Cohesion: This force is responsible for phenomena like water forming droplets and the surface tension that allows some insects to walk on water.
• Capillarity: This is not related to cohesion directly, but rather to the movement of liquid within narrow spaces without the assistance of external forces, usually due to a combination of cohesion and adhesion.
• Adhesion: This is the force of attraction between unlike molecules, such as water sticking to the surface of a glass.
• Surface Tension: While related to cohesion, this specifically refers to the effect caused by cohesive forces at the surface of a liquid, which makes the surface act like a stretched elastic membrane.

In summary, **cohesion** is the force that keeps the molecules of the same substance, like water, attracting each other.