Scientists that contributed in atomic theory

John Dalton

Oct 30, 1803

Proposed his modern theory of atom. He said that:
1 - Elements are made of extemely small particles, called atoms
2- Atoms of a given element are identical in size, mass, and other properties; atoms of different elements differ in size, mass, and other properties.
3- Atoms cannot be subdivided, created, or destroyed.
4- Atoms of different elements combine in simple whole-number ratios to form chemical compounds.
5- In chemical reactions, atoms are combined, separated, or rearranged.

Thomas Young

Nov 24, 1803

He did some contributions science on the subject light. He figured out the wave theory of light.

Amedeo Avogadro

Jan 12, 1811

At a specific temperature and pressure equal volumes of two gases will contain the same number of atoms.

Sir William Crookes

Jan 12, 1863

First person to investigate cathode rays

JJ Thomson

Oct 29, 1897

JJ Thomson identified the existance of electrons. His theory stated that atoms were round. Plum pudding model

Albert Einstein

Jan 12, 1905

He found a way to prove atoms exist by using his quantum physics theories

Ernest Rutherford

Oct 31, 1911

During the gold foil experiment rutherford found the nucleus and named the proton

Niels Bohr

Oct 31, 1913

Based on Rutherfords model he applied quantum theory assuming electrons moved in stationary orbits.

Henry Moseley

Nov 1, 1913

He provided a experimental evidence to Niels Bohr's theory,

Max Planck

Jan 12, 1918

Contributed to Quantum Theory

Louis De Brogile

Oct 31, 1924

He developed the thesis to wave mechanics.

Erwin Schrödinger

Oct 31, 1926

He made a mathematical model using a combination of wave behaviour equations and Louis de Brogile equations.

Werner Heisenberg

Jan 12, 1927

He discovered the Uncertainty Principal which states that excact location and energy of an electron can not be determined.

James Chadwick

Oct 31, 1932

Proved the existance of neutrons