These forces tend to cause colloidal particles to aggregate or to flocculate.

They can cause explosions, toxic fumes, radioactive particles, gases, or vapors when heated, compressed, or mixed with water.

Electrostatic charges like those that occur when a person rubs a plastic balloon against a sweater can cause particles of anthrax to clump together.

Sedimentation is the collective name for processes that cause mineral and/or organic particles (detritus) to settle and accumulate or minerals to precipitate from a solution.

As the gas from the explosion cooled, various physical forces caused particles to stick together.

First, wind causes small particles to be lifted and therefore moved to another region.

Compaction may cause fine particles to move into direct contact with their neighbours so a high initial porosity may become drastically reduced with burial.

The man rubbed his beard thoughtfully, causing various particles to cascade into the little bowls in his tray.

Uneven distribution of gas across the retort can result in blockages when hot spots cause particles to fuse or disintegrate.

This would cause charged particles that encounter the tethers to have their pitch angle changed, thus over time dissolving the Van Allen belts.