Rutherford Alpha Particle Scattering Experiment

Rutherford atomic theory

Rutherford had remarked that it is not in nature of things for any one man to make a sudden, violent discovery. Science goes step by step and every man depends on the work of his predecessor. The journey from John Dalton's atomic theory to the modern structure of an atom is a long and arduous one. The Daltonian atom is conceived to indivisible particles capable of independent existence.

The modern structure of an atom

Today an atom of the chemical elements or molecules is considered to be made up of tiny nucleus carrying neutron and protons. This tiny nucleus has around itself a certain number of negatively charged particles of negligible mass, called electrons, arranged in a definite order.

Thus an atom can be divided into small particles like electron, proton, and neutron. These particles are known as the elementary particles of an atom and electron configuration of the atom holds the key to the chemical reaction.

To describe the structure of an atom several atomic theories are proposed namely the Rutherford model, Bohr’s model, and Summerfield model for Azimuthal quantum number.

Rutherford Model of an atom

Rutherford's atomic model proposed that a very small positive nucleus was considered surrounded by electrons. Such energy levels of the system were not stable if the electron is in rest. Therefore it was proposed that the electrons were moving in circular orbits around the nucleus so that the Coulombic attraction between the nucleus and the electron was equal to the centrifugal force of the electron.