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Period: 460 BCE to 370 BCE
Democritus
A greek philosopher who is also known as the "laughing philosopher" theorized that atoms move around in an infinite void. (Stanford Encyclopedia of Philosophy) -
Period: 427 BCE to 348 BCE
Plato
A greek philosopher that theorized that molecules in the solid state were triangles and not spheres. He believed this because he believed that would make them fit together better and create different shapes. (The collector) -
330 BCE
Solar system model
A model created in 330 BCE to show the relative size of the planets to each other. (Twinkl.ie and Wikipedia -
Period: 1300 to
The Alchemists
Alchemists worked for very long hours to transmute metals into gold. (E&T Magazine) -
Period: to
Robert Boyle
The first modern chemist, and an alchemist. He worked on absolute pressure and volume of gas. (Wikipedia) -
Period: to
Antoine Lavoisier
A French Chemist who worked on biology and chemistry. He worked on how oxygen plays a role in combustion. He also predicted Silicon. (Wikipedia) -
Period: to
John Dalton
An English chemist that introduced the Atomic Theory. The Atomic theory is the scientific theory that all matter is made up of atoms. (Wikipedia) -
Period: to
Amedeo Avogadro
An Italian scientist that claimed that gases with equal volume and the same temperature and pressure contain the same amount of molecules. (Britannica) -
Billiard Ball Model
John Dalton created the model with the invasion that Atoms were tiny solid spherical balls with holes in them to hook with other atoms and create things. -
Period: to
Dimitri Mendeleev
A Russian scientist that developed the classification of the elements, also known as the periodic table. (Britannica) -
Period: to
J. J. Thomson
British physicist that calculated that electrons were smaller than atoms. He also found isotopes. (Wikipedia) -
Period: to
Pierre and Marie Curie
A married scientist couple that did research on radiation. Created the theory of radiation. They also discovered polonium. (Wikipedia) -
Period: to
Robert Millikan
Was an American experimental physicist. He worked on the photoelectric effect and elementary electric charge. He theorized that electrons have a quantifiable electric charge. (NobelPrize.org) -
Period: to
Ernest Rutherford
A New Zealand Physicist that was known as the "father of nuclear physicist" He theorized that atoms have a nucleus, and he discovered radon. (Wikipedia) -
Period: to
Albert Einstein
He was a German theoretical physicist that created the theory of relativity. Which is the theory that there is no absolute reference frame. He also worked on quantum mechanics. (Wikipedia) -
Period: to
Neils Bohr
A Danish physicist that theorized the atomic structure of atoms. (Wikipedia) -
Period: to
Henry G. J. Mosley
A English Physicist that created the concept of the Atomic Number, and that they contain a nucleus. (Wikipedia) -
Period: to
James Chadwick
A British scientist that discovered that in the nucleus of an atom there are also neutrons. (Study.com) -
Plum Pudding
J. J. Thomson created the Plum Pudding Model. The model shows how electrons are embedded into an atom's positive charge -
Electron Cloud Model
A model that shows how electrons orbit around the nucleus. (Wikipedia)