In a chemistry lab, Rina took some mercury and water in two test tubes separately. Then she drained off both the liquids and on observing the emty test tubes, found some difference. Can you guess what the difference is ? Explain with appropriate reasons.

Explanation

### Step-by-Step Solution:

1. **Observation of Test Tubes**: Rina took two test tubes, one containing mercury and the other containing water. After draining both liquids, she observed that the test tube that had water showed water droplets on its inner surface, while the test tube that had mercury appeared completely dry.

2. **Understanding Adhesive and Cohesive Forces**:
- **Cohesive Force**: This is the force of attraction between similar molecules. In the case of mercury, the cohesive forces are stronger than the adhesive forces. This means that mercury molecules are more attracted to each other than to the surface of the test tube.
- **Adhesive Force**: This is the force of attraction between different molecules. In the case of water, the adhesive forces are stronger than the cohesive forces. This means that water molecules are more attracted to the surface of the test tube than to each other.

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