Surface tension arises out of

Options

A. repulsive forces
B. cohesive forces
C. electrostatic attraction
D. friction

Answer

To solve the question "Surface tension arises out of," we need to understand the concept of surface tension and the forces involved.

### Step-by-Step Solution:

1. **Define Surface Tension**:
Surface tension is defined as the force that acts at the surface of a liquid, causing it to behave like a stretched elastic membrane. It is responsible for the shape of liquid droplets and the ability of some objects to float on a liquid surface.

**Hint**: Remember that surface tension is related to the behavior of liquids at their surface.

2. **Identify the Forces Involved**:
Surface tension arises due to intermolecular forces. Specifically, it is the result of cohesive forces, which are the attractive forces between molecules of the same substance.

**Hint**: Think about how molecules interact with each other in a liquid.

3. **Cohesive Forces**:
Cohesive forces are the forces that hold the molecules of a liquid together. In a liquid, each molecule is attracted to its neighboring molecules, creating a net inward force at the surface. This inward force is what gives rise to surface tension.

**Hint**: Consider how the molecules at the surface differ from those in the bulk of the liquid.

4. **Conclusion**:
Since surface tension is caused by the cohesive forces between the molecules of the same substance, we can conclude that surface tension arises out of cohesive forces.

**Hint**: Remember that cohesive forces are specific to molecules of the same type, which is key to understanding surface tension.

### Final Answer:
Surface tension arises out of cohesive forces.