Soap bubbles can be formed floating in air by blowing soap solution in air, with the help of a glass tube, but not water bubbles. It is because

Options

A. The excess pressure inside water bubble being more due to large surface tension
B. The excess pressure inside water bubble being less due to large surface tension
C. The excess pressure inside water bubble being more due to large viscosity
D. The excess pressure inside water bubble being less due to less viscosity

Explanation

To understand why soap bubbles can float in air while water bubbles cannot, we need to analyze the concepts of surface tension and excess pressure inside the bubbles.

### Step-by-Step Solution:

1. **Definition of Surface Tension**:
- Surface tension is the property of a liquid that causes its surface to behave like a stretched elastic membrane. It is a result of cohesive forces between liquid molecules.

2. **Excess Pressure in Bubbles**:
- The excess pressure (ΔP) inside a bubble is given by the formula:
\[ \Delta P = \frac{4S}{R} \]
where \(S\) is the surface tension of the liquid and \(R\) is the radius of the bubble.

3. **Comparing Surface Tension of Water and Soap**:
- Water has a higher surface tension compared to soap solution. This means that for a given radius, the excess pressure inside a water bubble will be greater than that inside a soap bubble.

4. **Effect of Excess Pressure**:
- Since the excess pressure is higher in water bubbles due to the larger surface tension, water bubbles are more prone to collapse. The higher pressure makes it difficult for them to maintain their shape and float in the air.

5. **Behavior of Soap Bubbles**:
- Soap bubbles, on the other hand, have a lower surface tension. This results in lower excess pressure inside the soap bubbles, allowing them to float and maintain their shape in the air.

6. **Conclusion**:
- Therefore, soap bubbles can float in air because the lower excess pressure (due to lower surface tension) allows them to remain stable, while water bubbles cannot float due to higher excess pressure (due to higher surface tension) which leads to their collapse.

### Final Answer:
Soap bubbles can float in air because the excess pressure inside the soap bubble is less due to lower surface tension compared to water bubbles, which have higher excess pressure due to higher surface tension.

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