Rutherford Scattering Experiment

Rutherford, scattering experiment

                THE DISCOVERY OF THE NUCLEUS

Prior to the discovery of the nucleus, the atoms where believed to contain positive and negative charges equally distributed throughout, in a model proposes by john  Jacque Thompson  called the plum pudding model.

Sir Ernest Rutherford with aid of  two of his student ,Han Geiger and Madsen   carried out an alpha scattering experiment to which led to the discovery of the nucleus.

 A beam of alpha particles which is a helium nucleus; therefore positively charged are passed through an atom(a thin gold foil),  the ray coming from the alpha source were observed to behave in three ways,

 A large percentage of them passed through the gold foil (atom) uninterrupted, some few percentage of them  near the center of the atom where deflected  and small percentage at the centre where reflected back completely as show in the sketch below.

Those alpha particles that  that pass through  the atom uninterrupted shows the atom is almost empty , those that that where deflected indicate that there is massive particles at the center, that is heavier than the alpha particles and therefore capable of deflecting them, while the few that were reflected back and returned at the center shows that the center has same charge as the alpha particles and therefore like charges must repel.

 From the above it indicate the atom is almost empty with, it center very massive and positively charged, hence the nucleus is located at the center of atoms, very heavy and positively charged.

 It was  with this discovery of the nucleus that the concept of nuclear and particle physics came into being. The above discovery has remodeled the general perception about  atoms and the new Rutherford atomic models was formulated.