The factor responsible for lower mercury level in a capillary tube is

Options

A. high density
B. surface tension
C. liquid state
D. viscosity resistance

Explanation

To understand the factor responsible for the lower mercury level in a capillary tube, we can break down the explanation into clear steps:

### Step-by-Step Solution:

1. **Understanding the Capillary Tube**:
- A capillary tube is a thin tube where liquids can rise or fall due to surface tension and the interactions between the liquid and the tube material.

2. **Identifying the Liquid**:
- In this case, the liquid in question is mercury, which is a metal that is liquid at room temperature.

3. **Cohesive Forces vs. Adhesive Forces**:
- **Cohesive Forces**: These are the intermolecular forces that hold the molecules of the same substance together. In mercury, these forces are strong due to metallic bonding.
- **Adhesive Forces**: These are the forces of attraction between different substances, such as mercury and the glass of the capillary tube.

4. **Analyzing the Interaction**:
- When mercury is in contact with glass, the cohesive forces between mercury molecules are stronger than the adhesive forces between mercury and glass. This means that mercury tends to stick to itself more than it sticks to the glass.

5. **Resulting Behavior**:
- Because the cohesive forces dominate, mercury does not rise in the capillary tube as much as it would if the adhesive forces were stronger. This results in a lower level of mercury in the capillary tube.

6. **Conclusion**:
- The lower mercury level in the capillary tube is primarily due to the cohesive forces being greater than the adhesive forces between mercury and the glass.

### Final Answer:
The factor responsible for the lower mercury level in a capillary tube is that the cohesive forces in mercury are greater than the adhesive forces between mercury and the glass.

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