The surface tension of liuid at its boiling point

Options

A. becomes zero
B. becomes infinity
C. is equal to the value at room temperature
D. is half to the value at the room temperature

Explanation

To solve the question regarding the surface tension of a liquid at its boiling point, we can follow these steps:

### Step 1: Understand Surface Tension
Surface tension is a property of liquids that describes the elastic-like force existing at the surface of a liquid. It is caused by the cohesive forces between liquid molecules.

**Hint:** Remember that surface tension is influenced by temperature.

### Step 2: Investigate the Effect of Temperature on Surface Tension
As the temperature of a liquid increases, the kinetic energy of the molecules also increases. This increased energy causes the molecules to move apart, which reduces the cohesive forces at the surface.

**Hint:** Think about how heating a liquid affects the movement of its molecules.

### Step 3: Identify the Behavior at the Boiling Point
At the boiling point of a liquid, the temperature is high enough that the cohesive forces are significantly weakened. In fact, at the boiling point, the surface tension of the liquid approaches zero.

**Hint:** Recall what happens to a liquid when it reaches its boiling point.

### Step 4: Conclusion
Therefore, the surface tension of the liquid at its boiling point is zero.

**Final Answer:** The surface tension of the liquid at its boiling point becomes zero.