Discovery of Nucleus

Rutherford through the good foil experiment discovered nucleus.

In 1909, Rutherford, along with his colleagues Hans Geiger and Ernest Marsden, performed an experiment in which a thin sheet of gold foil was bombarded with alpha particles. 

Alpha particles are fast moving positively charged particles emitted by radioactive substances.

Back then, Thomson’s Plum Pudding Model was prevalent and it assumed that the atom was a positively charged sphere with electrons embedded within it, resembling the plums in a pudding.

Results of Rutherford Experiment:

However, the results of the experiment were unexpected. 

Most of the alpha particles passed straight through the gold foil with little deflection, as predicted by the Thomson model. 

However, a small fraction of the alpha particles were deflected at large angles, and a few even bounced back in the direction from which they came.

Interpretation of Results:

Rutherford interpreted these results as:

The atom’s positive charge and most of its mass is concentrated in a tiny, dense region at the center, which he called the nucleus. 

The nucleus was surrounded by a cloud of negatively charged electrons. 

This new model became known as the Rutherford model or the nuclear model of the atom.

How Rutherford experiment laid foundations of nuclear physics?

 

The discovery of the nucleus revolutionized the understanding of atomic structure and laid the foundation for modern nuclear physics.

 It paved the way for discoveries such as the identification of subatomic particles like protons and neutrons and the development of quantum mechanics.