Question

Delta formation at the mouth of 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: Deltas are formed when the rivers empty their water and settle into another water body like ocean. The formation of delta is a good example of colloid where the coagulation takes place between the positive and negative charged particles present in both the water bodies.

Complete step by step answer:
The lyophobic sols are stable due to the presence of charge present on the colloidal particles. When the charge is removed by some action, the colloidal particles come close to each other and coagulate and as a result they settle down under the gravitational force. The process of settling of colloidal particles is known as coagulation or flocculation of sol.
Delta formation is an excellent example of colloids where the river water is a colloidal solution of clay which contains negative charged particles and the sea water contains a number of electrolytes inside it. When the river water comes in contact with the sea water and inter-mix with each other, the electrolytes (positive charge particles) present in the sea water coagulate the colloidal solution (negative charged particles ) which results in the deposition and delta is formed.
Thus, delta formation at the mouth of the river takes place by Coagulation of positive salt ions and negative river particles.

So, the correct answer is Option B.

Note: The delta formed have different shapes depending upon the quantity of sediments deposited in the river. When the river flows, it collects up sediment from the river bed,banks, and debris on the water.