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427 BCE
Plato
Plato introduced the idea that atoms are idea geometrical forms that break down into triangles. -
400 BCE
Democritus
Democritus named the building blocks of matter atoms, meaning invisible. -
Robert Boyle
Robert Boyle discovered that atoms must exist, due to the relationship between pressure and the volume of gas. -
The Alchemists
The Alchemists made their major atomic discovery in the 17th century, when they realized that elements are pure substances that cannot be separated into any other chemical components.
1669 was when the first element was discovered -
Antoine Lavoisier
Antoine Lavoisier defined that matter was composed of atoms that were not created or destroyed during chemical reactions. -
John Dalton
John Dalton was the person who, in 1803-1808 proposed the atomic theory -
Billiard Ball Model
Proposed by John Dalton -
Amedeo Avogadro
Avogadro made a law that states that the equal volume of gases at the same pressure and temperature contain an equal number of molecules. -
Dimitri Mendeleev
In 1867, Dimitri wrote symbols for chemical elements, putting them in order according to specific attributes. -
JJ Thomson
In 1897, JJ Thompson discovered that atoms are made of similar components. -
Pierre and Marie Curie
The Curies discovered two strongly radioactive elements polonium and radium. -
Plum Pudding Model
Created by JJ Thomson -
Albert Einstein
Albert Einstein, among other things, was able to fully prove through usage of evidence that atoms exist. -
Robert Millikan
Robert Millikan discovered the charge of an individual electron. -
Ernest Rutherford
Ernest Rutherford theorized that atoms have their charge concentrated in a very small nucleus. -
Henry G. J. Mosely
Mosely discovered that the frequencies of the x-ray of an atom are proportional to the square of whole numbers that are equal to the atomic number plus a constant. -
Solar System Model
Created by Nells Bohr -
Electron Cloud Model
By Erwin Schrodinger and Werner Heisenberg -
James Chadwich
In 1932, Chadwich was able to prove the existence of neutrons. -
Nells Bohr
Nells Bohr made fundamental contributions to understanding the atomic structure and quantum theory. He received a Nobel Peace Prize in Physics in 1992