Due to suface tension the suface of two moist grain act a suface attraction force upon each other and attracted to wards each other.
starch grains first soften, then absorbs water and swells in the presence of moist heat
I would have thought that once the (dry) grains were removed from the constraints of a sack, gravity would make them spread out. The only other thing would be, is that the grains are moist. This moistness would tend to make them keep in a more upright clump!
When grains move closer together, it is called compaction. This process involves reducing the pore space between grains, leading to a denser arrangement of particles.
Grains can move closer together through a process called compaction, where external pressure is applied to sediment layers, squeezing out excess water and air between the grains. This results in the grains packing more closely together, increasing the density and reducing the volume of the sediment.
Interlocking
Actin is thin, pulled together by myosin.
Close-packing is a term used to describe grains that fit tightly together with minimal space in between them. This arrangement maximizes the packing density of the grains.
Sand grains cemented together into solid stone are called sandstone. Sandstone is a sedimentary rock formed from the compression and cementation of sand grains over time.
Heavier sediments are more easily pulled down by gravity in slower waters. But they also have the chance to clump together with other sediments and become heavy enough to be pulled down. In faster waters, it pulls the grains and material apart before it can settle and has a stronger force than the pull of gravity.
A rock formed from grains stuck together would be Porous
convection
they fall in love