** Atom is the smallest particle
** Atom is indivisible
Democritus held that nothing could come from nothing, that everything is already in the world and it is merely a matter of combination and re-combination of eternal bits of immutable stuff called atoms that remain indivisible in and of themselves. Read more HERE
Democritus expanded the atomic theory of Leucippus. He maintained the impossibility of dividing things ad infinitum...
He explained the origin of the universe as follows : The original motion of the atoms was in all directions—it was a sort of “vibration” hence there resulted collisions and, in particular, a whirling movement, whereby similar atoms were brought together and united to form larger bodies and worlds.
Read more from Britannica Encyclopedia HERE