Which conclusion could be made from ernest rutherford’s gold foil experiment?
atoms are made up of mostly empty space.
atoms are mainly solid and block alpha particles.
the volume of the nucleus is large compared to the rest of the atom.
the mass of the nucleus is small compared to the rest of the atom.

Atoms are made up of mostly empty space.  The reason why this can be concluded is that the experiment showed that alpha articles can for the most part pass right through the foil.  This showed that the nucleus of the atom was very small and took 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.