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460 BCE
Democritus
Democritus was a philosopher who was born before the common era and essentially created the Atomic Theory and changed science forever. -
400 BCE
Democritus Atom Theory
Democritus created the atomic theory in 475 BC. Its main components being, matter is made up of atoms,they are indestructible and invisible. Democritus did not discover or even think about subatomic particles, he only made the idea of a complete atom nothing inside. His model helped other scientists, and people, understand the idea of an atom. -
John Dalton
John Dalton was a scientist in the late-18th century to mid-19th century who contributed a lot to the atomic theory. -
John Dalton Atomic Theory
John Dalton updated the atomic theory. He still kept the parts of matter made up of atoms, and they are indestructible and invisible. Dalton basically dove a little bit deeper. Stating that, all atoms of an element are identical in mass and properties and compounds are a combination of two or more different kinds of atoms. -
JJ Thomson
JJ Thomson who was born in the late-19th century. He would change the model and history of the atom forever. He was the first to discover a subatomic particle in an atom. -
Ernest Rutherford
Ernest Rutherford was born in the late-nineteenth century. Rutherford did not make his atomic contribution until the early-twentieth century in 1911. He essentially discovered the model that we use today just that he did not go in depth in the nucleus as much as we did. -
Neils Bohr
Neils Bohr was physicist who worked with Rutherford. He went to the University of Copenhagen. He also made the Neils Bohr model in 1913 and was awarded the Nobel Prize in 1922. -
Erwin Schrödinger
Erwin was Quantum Physicist in the early 1900s. He studied at the University of Vienna. He discovered the way and where the electron moves in an atom. -
JJ Thomson's Plum Pudding Model
JJ Thomson used cathode rays negatively charged rays to find the mass of electrons. Thomson was the first to discover a subatomic particle. With having the idea of the subatomic particle in mind Thomson deducted that in an atom there is as well something positive. So his atomic model was like plum pudding. A positive matter with small electrons in it. -
Ernest Rutherford's Gold Foil Experiment
Ernest Rutherford gold foil experiment was arguably the most important discovery in a long time. In his experiment Rutherford shot alpha particles at gold foil. He initially thought that the alpha particles were all going to deflect according to Thomson's Plum Pudding model. To his surprise most of them went through the gold foil and that few were deflected back. Rutherford deducted that most of the atom is space, and that nucleus is at the center and there are electrons around the nucleus. -
Neils Bohr Model
Neils Bohr created this model in 1913. The old model which was the Rutherford one, did not specify where and how the electrons move in the atom. The Neils Bohr Model specifically focuses on the electrons, It shows that the electron moves in an electron shell or level and that the electron moves around those shells and gives off and takes energy when moving from level to level. -
The Quantum Mechanical Atom Model
The model was discovered by Erwin in 1924 and he changed the placements of the atoms and where they go and move. In this model the electrons move in a cloud and do not just move around in a circle. The Quantum Mechanical Atom Model also explains why the electron moves from level to level.
