When a river enters the sea, a delta is formed . Formation of delta is due to

Options

A. Peptization
B. Coagulation
C. Emulsification
D. Dialysis

Answer

To answer the question "When a river enters the sea, a delta is formed. Formation of delta is due to:", we can break down the explanation into clear steps:

### Step-by-Step Solution:

1. **Understanding the Environment**:
- When a river flows into the sea, it carries with it various sediments, including clay, sand, and other particulate matter. This mixture is often in the form of a colloidal solution.

2. **Identifying the Nature of River Water**:
- The river water is a colloidal solution, which means it contains small particles that are suspended in the water. These particles can include organic and inorganic materials.

3. **Understanding Sea Water**:
- Sea water is salty and behaves as an electrolyte. This means it contains ions that can influence the behavior of colloidal particles.

4. **Coagulation Process**:
- When the colloidal river water mixes with the electrolyte-rich sea water, a coagulation reaction occurs. This is because the ions in the sea water neutralize the charges on the colloidal particles, leading to their aggregation.

5. **Formation of Delta**:
- As the colloidal particles aggregate and settle, they form larger particles that eventually settle at the river mouth. This accumulation of sediments leads to the formation of a delta.

6. **Conclusion**:
- Therefore, the formation of a delta when a river enters the sea is primarily due to the coagulation of colloidal particles caused by the presence of electrolytes in sea water.

### Final Answer:
The formation of a delta is due to **coagulation** of colloidal particles in river water when it mixes with sea water.