Specific Surface of a spherical soil particle having 1.5 mm diameter is

The specific surface area of a soil sample is the total surface area contained in a unit mass of soil. Soils with high specific surface areas have high water-holding capacities, more adsorption of contaminants, and greater swell potentials.
The specific surface is calculated by the surface area of the solid particles divided by the mass of the solid particles.
The specific surface of a spherical soil particle having a 1.5 diameter is 4.