Atoms for Democritus had two properties: size and shape.
Atoms connect each other
in different orders (stoichometry and structural formula?) and create different
substances.
Atoms are in permanent
motion and collide each other (like in Boltzmann’s perfect gas model?),
their motion decides about their mass (the mass of proton results not from
gluons’ rest mass but from their motion, thanks to Einstein’s m=E/c2)
Atoms emit fluids
(photons?) which can be observed
