An interesting thing happens when you group particles together. The combined mass or volume of the resulting object grows faster than the surface area. Especially in a spherical grouping, the most efficient geometry for volume versus surface area, as the volume increases more of the particles become internal to the overall structure. Because of this property of grouped particles a single particle will have the greatest surface area per volume than a grouped structure. This greater surface area per mass relationship makes smaller particles easier to retain in suspension than larger groupings of particles.
interactivity