Question

Why large deflection were not observed in Rutherford experiment ?

Answer 1

Dear student,
Rutherford developed an experiment where he bombarded very thin gold foil with $\alpha$-particles. High energy particles were directed at a thin gold foil. There was ZnS screen around the gold foil. Whenever the $\alpha$-particles struck the ZnS screen, a small flash of light was produced.
As given by the Thomson model that the positive charge is evenly distributed all over the atom, Rutherford expected that the high energy $\alpha$- particles would slow down when they would interact with the positive ion in the atom. He also expected that particles would deflect only by small angles. But the observations were unexpected.
A large number of $\alpha$-particles were undeflected which proved that most of the space in the atom is empty.
Few of the particles were deflected by small angles.
Very few $\alpha$-particles were deflected by large angles which suggested that the positive charge of the atom is present in a small space of the atom.

Thus, we can say that large deflections were not observed in the Rutherford experiment because most of the space in the atom is empty.


Regards