[Manipal 2008] Deflection of a few α-particles back on hitting a thin gold foil shows that
0.Nucleus is heavy
1.Nucleus is small
2.Both: nucleus is heavy and small
3.Electrons create hindrance for α-particles
Explanation
Rutherford's gold foil experiment showed that the nucleus is both small (most α-particles pass through) and very heavy/dense (a few are deflected back).