bro,
that's great but don't just stop there! the mass of the atom is largely dependent on the nucleus, which folks understand as protons and neutrons, which are essentially up quarks and down quarks (which gives it its charges), coupled with gluon and muons, not forgetting other particles like neutrinos. must also remember to mention the electrons that orbits the nucleus too.
last noted that the size of the nucleus with respect to the size of the atom is akin to a football in a football field, the electrons would then be described as flies flying around that field all around that football