Swimming for a long time in salt water makes the skin of one's finger tips wrinkled. Which property is responsible for this observation ?

Answer

To understand why swimming for a long time in salt water makes the skin of one's fingertips wrinkled, we can break down the explanation into several steps:

### Step-by-Step Solution:

1. **Understanding Osmosis**:
- Osmosis is the process by which solvent molecules move through a selectively permeable membrane from a region of lower solute concentration to a region of higher solute concentration. In this case, the skin acts as a selectively permeable membrane.

2. **Concentration of Salt Water**:
- Salt water has a higher concentration of solutes (salt) compared to the fluids inside the cells of the skin. When you immerse your fingers in salt water, the concentration gradient causes water to move out of the skin cells.

3. **Movement of Water**:
- Due to osmosis, water from the skin cells (which have a higher water potential) moves to the salt water (which has a lower water potential). This results in the skin cells losing water.

4. **Swelling of the Epidermis**:
- As the skin cells lose water, the outer layer of the skin, known as the epidermis, begins to swell. This swelling leads to the formation of wrinkles on the fingertips.

5. **Conclusion**:
- Therefore, the wrinkling of the fingertips after prolonged exposure to salt water is primarily due to the osmotic movement of water out of the skin cells, causing the epidermis to swell.

### Final Answer:
The property responsible for the wrinkling of fingertips after swimming in salt water is **osmosis**, which leads to the movement of water out of the skin cells due to the higher concentration of salt in the surrounding water.

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