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Democritus

500

"All matter is made up from atoms" This was the birth of the study of atoms. He stated atoms cannot be divided to any smaller unit and therefore are invisible

John Dalton

Oct 25, 1803

John Dalotn made the impacting discorvery of Atmoic Theory. I other words the nature of matter.

Henri Becquerel

Jun 17, 1896

Henri discoverd Radioactivity. While studying the effect of x-rays on photographic film this was discoverd.

J.J. Thompson

Oct 25, 1897

J.J. Thompson discored the electron and isotope. Also how th electron consist of negative charges. This was discoverded by studing the properties of cathrode rays.

Marie & Pierre Curie

Oct 24, 1898

The Couple was well knwon for the discovery of Radium and Polonium. Both elements were discoverd by studying for a sample of pitchblende had at least one radioactive element.

Robert Millikan

Aug 15, 1908

Robert is known for discorvering the charge of an electron. The "Oil drop Experiment" contstructed at the university of Chicago came to this discovery.

Ernest Rutherford

Oct 24, 1920

Rutherford discoverd the Proton. His well known "Gold Foil experiement" Led to the Proton. The Rutherfordmodel was the basic model of an atoms structure.

Neils Bohr

Oct 25, 1922

Bohr is the creator of Quantam theory. This stating motion in the atom is discrete or quantanized.

James Chadwick

Nov 18, 1945

James discoverd an unknown partcle.This unknown partle is the Nucleus. He produced a series of Experiements at The University of Cambridge to come to his findings.

Quantum Model

Oct 26, 1964

This Model was contributed by a range of scientist. It mainly consist of scientist.

Aristotle

Mar 2, 2022

Aristotle created studies of how elements are based off of four, Air, Earth, Water, and Fire. this in which convered a basis for chemistry.