What is the shape of a liquid meniscus in a capillary tube dipped in mercury?

Answer

To determine the shape of the liquid meniscus in a capillary tube dipped in mercury, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Meniscus**: The meniscus is the curve at the surface of a liquid in a container. It can be either concave or convex depending on the adhesive and cohesive forces at play.

2. **Identify the Liquid and Material**: In this case, the liquid is mercury, and the capillary tube is typically made of glass.

3. **Analyze the Angle of Contact**: The angle of contact (θ) between mercury and glass is greater than 90 degrees. This indicates that the cohesive forces (forces between mercury molecules) are stronger than the adhesive forces (forces between mercury and glass molecules).

4. **Determine the Shape of the Meniscus**: Since the angle of contact is greater than 90 degrees, the mercury will not rise in the capillary tube. Instead, it will form a convex meniscus, curving outward.

5. **Visualize the Meniscus**: The shape of the meniscus can be visualized as a dome or a spherical cap, which is characteristic of liquids with a high angle of contact with the walls of the container.

6. **Conclusion**: Therefore, the shape of the liquid meniscus in a capillary tube dipped in mercury is convex.

### Final Answer:
The shape of the liquid meniscus in a capillary tube dipped in mercury is convex.

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