Eye lubricants and tears dry up in the air and may form scratchy particles.

A few protons and electrons can form bigger particles called atoms and molecules.

It is stable, too; that is, left to itself, it Will not break down to form other particles.

These clusters coalesce to form nuclei, which later form stable particles.

In some basins a flocculant may be added to help smaller particles stick together and form larger particles.

These stones develop because cholesterol and pigments in bile sometimes form hard particles.

Dust particles may form larger particles resulting in "grain plasmas".

Scientists call the force that holds quarks together to form larger particles the strong nuclear force.

Opacifiers must also form small particles in the system.

As they cool, the atoms supposedly bond to each other in various ways and eventually form particles of a million or more atoms.