Atomic Theory Project

Democritus

442

Democritus and his teacher Leuippus came up with that all matter is composed of indivisible elements.

John Dalton

Oct 9, 1803

Dalton developed theory that matter is simply composed of atoms of different weights, also he proposed that atoms are spherical and are in constant motion

Radiation, Energy, and the atom

Oct 9, 1898

Pierre and Cuire theorized that radio active particles cause atoms to break down, then releasing radiation that takes the form of energy and subatomic particles

Electrons discovered

Oct 9, 1898

JJ Thompson discovered the electron, using particles of Cathode Ray

Early Quantum Theory develpoed

Oct 9, 1900

Planck introduced the Quantum Theory, stating that electromagnetic energy could only be emitted in quantized form.

Charge of an Electrom measured

Oct 9, 1908

Millikan measures the charge of a single electron

Strucutre of an atom developed

Oct 9, 1909

Rutherford developed the theory for the structure if the atom. He used the Gold Foil experiment and demonstrated for the first time the existence of the atomic nucleus.

Cathode Ray Tube

Oct 9, 1911

JJ Thompson constructed a primitive cathode ray tube. He had discovered the electron is like plum pudding or a choc. chip cookie

Bohr improves the atomic model

Oct 9, 1913

Bohr develpoed the Bohr atomic model, and chemical properties being determined by how many electrons are in the outter orbit

The neutron is discovered

Oct 9, 1931

Chadwick discovered the neutron component of the atomic nucleus

Nuclear Fission developed

Oct 9, 1938

Hahn, discovered nuclear fission

Heisenberg Quantum Theory

Oct 9, 1957

Atomic nucleus, ferro magnetism cosmic rays & subatomic particles

Schodinger Quantum Theory

Oct 10, 2013

Wave mechanics, formulated the wave equation