Sodium ion causes dispersion of clay because

A. It has lower charge density

B. It's a heavy metal

C. It is highly mobile

D. It has a small size of hydrated state

Answer: Option A

Solution(By Examveda Team)

The clay particles are bound together because of force between them, but the presence of a large number of huge sodium ions which has lower charge density disrupts the force between the particles and hence it causes dispersion of clay particles especially when the soil is wet.