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500 BCE
The Alchemists
The Alchemists found a substance that made silver or gold with more common elements. -
427 BCE
Plato
Introduced the atomic theory with atoms were ideal geometric figures. -
400 BCE
Democtritus
Theorized that unsplit table small atoms made all materials in bodies. -
Robert Boyle
Published the Scopticel about how all matter is composed of important particles from which all materials are constructed. -
Antoine Lavoisier
Found out the reactants and the total mass of products in a chemical reaction is always the same. -
John Dalton
Theorized that all matter was made of atoms, indestructible building blocks, and were indivisible. Different elements were made of different sized and mass. -
Billiard Ball Model
Didn't show any nucleus or electrons and defined an atom to be a ball like structure. -
Dmitri Mendeleev
Proved the arrangement of elements in the order of their increasing atomic weights. -
Robert Milikan
Found out that electrons charge was always a multiple of precisely determined charges. -
JJ Thompson
Theorized that tiny negatively charged subatomic electrons or particles were found in atoms. -
Pierre and Marie Crie
Theorized one of the reason atoms break down are radioactive particles. -
The Curies
Discovered the existence of the element's radium and polonium. -
Plum Pudding Model
Was made to explain two properties of the atom. -
Albert Einstein
Einstein helped revolutionize science through the use of statics and probability by mathematically proving atoms exist. -
Neils Bohr
Proposed an atomic structure thing that said the inner orbit of an atomic held less electrons than the outside. -
Solar System Model
Showed hoe the electrons orbit about the nucleus at different distances. -
Henry G. J. Mosely
Proposed that the number of positive charges in the atomic nucleus is the atomic number. -
Ernest Rutherford
Proposed that nearly all of an atom is empty space, so when alpha particles go through the empty space the nucleus has a very little reaction. -
Electron Cloud Model
Predicts the likely location of the electron based on a fraction of probability. -
Erwin Schrodinger
Created the first electron cloud model. -
James Chadwich
Discovered the Neutron in atoms. -
Almadeo Avogrado
Discovered that elements were not only found in individual atoms but instead be found in molecules.