Question

Delta formation at the mouth of the river takes place by:
A. coagulation of negative salt ions and positive river particles
B. coagulation of positive salt ions and negative river particles
C. coagulation of positive salt ions and positive river particles
D. coagulation of negative salt ions and negative river particles

Answer 1

Hint : We have studied that when a river reaches to the sea or a lake the speed of the water of the river slows down and loses the power to carry sediment. Then the sediment is dropped at the mouth of the river. Some rivers drop so much sand, mud and pebbles that tides and waves cannot carry them away so they built a layer forming a delta.

Complete step by step solution:
We know that the particles of the river contain charged particles of clay, sand, pebbles and other materials. Sea water is a complex mixture of water and electrolytes. Sea water contains dissolved ion more than normal water. When river water comes in contact with sea water, the sentiments of the sea water starts coagulating. Sea water coagulates the suspended colloidal particles (Sediment). The river contains negative charge particles suspended in the water. Hence delta is formed because of positive salt ions and negative river particles. So option B is correct answer this question that is delta formation at the mouth of the river takes place by coagulation of positive salt ions and negative river particles

Note : Delta used to have different shapes depending on the amount of the sediment deposited at the river. When the river water reaches the sea it slows down and river charged particles come in contact with electrolytes of sea water. We have concluded that the distribution of surface charges of sediments of river and sea water is the reason for delta formation at the mouth of the river.