Define Surface tension. Write its formula. What is its S.I unit?

Explanation

### Step-by-Step Solution:

**Step 1: Definition of Surface Tension**
Surface tension is defined as the tendency of a liquid's surface to shrink and minimize its surface area due to cohesive forces between liquid molecules. This phenomenon occurs because the molecules at the surface experience a net inward force, which results in the liquid behaving as if its surface is covered with a stretched elastic membrane.

**Step 2: Formula of Surface Tension**
The formula for surface tension (γ) is given by the ratio of the force (F) acting along the surface to the length (L) over which the force acts. Mathematically, it can be expressed as:
\[
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