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492 BCE
Democritus
Democritus lived in Abdera. He was the first to propose an atomic universe. To make this discovery Democritus took a sea shell and broke it over and over until he had only a fine powder. Then he took the smallest grain and tried to break it. It would not budge. He then realized that this was the basic building block. An Atom. Many believe that with out his major finding that the science world would not be where we are now. -
340
Aristotle
Aristotle lived from 384-322 BC. He described the 5 elements of matter. Water, Fire, Earth, Air, and starts/ planets. He did not really have any experiments back his thinking up except for common sense. His theory was later proved wrong but was one of the first scientist of his kind. Witch gave him praise in the science world. A fun fact about him is that he helped Alexander the Great while in power. -
Billiard Model
The Billiard Ball Model envisioned them as solid, hard spheres, like billiard balls, so he used wooden balls to model them. Three of his model atoms are pictured in the Figure below. It was proposed by John Dalton. -
Lucas Model
The Lucas Model was proposed by Joseph Lucas. It proposes that protons and neutrons are based around a charged ring. -
John Dalton
John lived from 1766 to 1844. Dalton's experiments on gases led to his discovery that the total pressure of a mixture of gases amounted to the sum of the partial pressures that each individual gas exerted while occupying the same space. An interesting fact is that John started teaching at a local high school when he was 12. -
Elemental Model
John Dalton Proposed the Elemental Model which was a chart that showed atoms
And their differences using symbols and words. -
JJ Thomson
JJ lived from 1856-1940. In this time he made his famous discovery of the electron. He made this discovery by experiencing with a Crookes, or cathode ray, tube. A cool facts is that he was awarded a Nobel Prize for his science discovery. -
Marie Curie
Marie Curie lived from 1867-1934. She contributed 2 new elements that's called radium and polonium. She discovered this when doing research about radioactivity. A fun fact about her is that she helped contribute to the invention of the ExRay. -
Max Planck
Max lived from 1858-1947. He contributed to the understanding of an Atom by giving a theory that describes nature at it's smallest scales of energy. Max used hot glowing matter to help make his theory. An interesting fact is that he attended college at the age of 16 years old. -
The Plum Pudding Model
The plum pudding model is a model of atomic structure proposed by J.J. Thomson in the late 19th century. Thomson had discovers that atoms are composite objects, made of pieces with positive and negative charge, an that the negatively charged electrons within the atom were very small compared to the entire atom. -
The Plum Pudding Model
The Plum Pudding Model is a model of atomic structure proposed by J.J. Thomson in the late 19th century. Thomson had discovered that atoms are composite objects, made of pieces with positive and negative charge, and that the negatively charged electrons within the atom were very small compared to the entire atom. -
Albert Einstein
Albert lived from 1879-1955. Albert made the Theory of Relativity. Albert determined that the laws of physics are the same for all non-accelerating observers. A fun fact about Einstein is that he was very good at playing the violin. -
Robert Millikan
Robert lived from 1868-1953. His studies helped determin the charge in an electron. Robert used his famous Plum Pudding Model to help him discover this finding that changed our thoughts on electrons. A fun fact about Robert is that along with many other scientist on this list he won a Nobel Prize. -
Nuclear Model
The Nuclear Model. The structure of the atom. Atoms contain three subatomic particles called protons, neutrons and electrons. The protons and neutrons are found in the nucleus at the centre of the atom. It was proposed by Ernest Rutherford. -
Niels Bohr
Niels lived from 1885-1962. Niels made a theory that states that the hydrogen atom on quantum theory that energy is transferred only in certain quantities. Niels used the already existing quantum theory proposed by Max Planck to create this theory that has further deepened our knowledge on atoms. An interesting facts about him is that he is the middle of 3 siblings. -
Toroidal Ring Model
The Toroidal Ring Model proposes instead of a single orbiting charge, the toroidal ring was conceived as a collection of infinitesimal charge elements, which orbited or circulated along a common continuous path or loop. In this configuration the charge elements circulated, but the ring as a whole did not radiate due to changes in electric or magnetic fields since it remained stationary. It was proposed by Niels Bohr. -
Bohr Model
Neil Bohr proposed the Bohr model which showed electrons in circular orbit around the nucleus with quantized values of angular momentum. -
Erwin Schrodinger
Erwin lived from 1887-1961. Erwin made the Atom model. He found this when looking deeper into the molecule of an atom. An interesting fact about Erwin is that he won a Nobel Prize for his great drawing. -
Wave Model
In the Wave Model of the Atom, the electrons in the atom have discrete energies and obey the Exclusion Principle. It was proposed by Erwin Schrödinger. -
Quantum Mechanical Model
The Quantum Mechanical Model of the atom uses complex shapes of orbitals , volumes of space in which there is likely to be an electron. It is based more on probability than actual certainties. It was proposed by Erwin Schrödinger.
