Rutherford

Since the previous atomic model (the Thomson model) argues that an atom is a sphere of positive charge with the negatively-charged electrons scattered like "raisins in a pudding", Rutherford and his students fully expected that an α particle will pass through the gold foil with just a slight deflection on the angles since the α

particle is weakly positively charged.

In the case of the experiment, some of the α

particles did not only deflect at very large angles, but some even bounced back straight to the origin!

Rutherford's experiment showed the existence of a nuclear atom - a small, positively-charged nucleus surrounded by empty space and then a layer of electrons to form the outside of the atom.