M.W.

The idea that matter is made of small, indivisible "pieces" has been around for thousands of years.
 * __//1st. The Ancient Greek Models//__**



In 1906, J.J. Thomson created a current of Negatively Charged Particles in a cathode-ray tube that were much smaller than an atom.
 * //__2nd. The Plum Pudding Model__//**

In 1908, Ernest Rutherford fired alpha particas (protons) at gold atoms and discovered that the center of the atom is densely packed and positivelu charged.
 * //__3rd. Rutherford's model__//**



In 1913, Neils Bohr introduced quantum mechanics into the atomic model
 * //__4th. Bohr's model__//**

In 1926, Erwin Schrodinger introduced probabilty into the structure of the atom.
 * //__5th. Schrodinger model__//**