Which one of the following is not part of john daltons atomic theory ?
a)all elements are composed of atoms
b) all atoms of the same element have the same mass
c)atoms contain subatomic particles
d) a compound contains atoms of more than one element

C) atoms contain subatomic particles.

John Dalton's atomic model was also known as a 'Billiard Ball Model' because he thought that all atoms were just simple spheres, and nothing complex inside.

An  atom  (ours, not carroll's) consists of a positively charged  nucleus, surrounded by one or more negatively charged particles called  electrons. the positive charges equal the negative charges, so the atom has no overall charge; it is electrically neutral. most of an atom's mass is in its nucleus; the mass of an electron is only 1/1836 the mass of the lightest nucleus, that of hydrogen. although the nucleus is heavy, it is quite small compared with the overall size of an atom. the radius of a typical atom is around 0.1 to 0.25 nanometres (nm), whereas the radius of a nucleus is about 10-6  nm.  *  if an atom were enlarged to the size of the earth, its nucleus would be only 200 feet in diameter and could easily rest inside a small football stadium.read more on -