As a result of the gold foil experiment it was concluded that an atom (1) contains protons, neutrons, and electrons(2)contains a small, dense nucleus(3)has positrons and orbitals (4)is a hard and invisible sphere

 It showed that the atom contains a small dense nucleus. The reason why this can be concluded is that the experiment showed that alpha particles can for the most part pass right through the foil.  This showed that the nucleus of the atom is very small and takes up a very small portion of the size of an atom since the nucleus is what would reflect the alpha particle.  If atoms were not mostly empty space, the alpha particles would have been bounced back and the opposite of what was observed would have happened (all or at least the majority would be bounced back instead the majority getting through with only a small portion being reflected back).

I hope this helps.  Let me know in the comments if anything is unclear.