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Greek Model (Democritus) and Leucipitus 460 BCE- 370 BCE
Democritus was a greek philosopher by the 400BC. This model was a physiological idea that everything can be broken down into a fundamental piece (The Atom); but it could not be tested at that time because the Greeks didn't have the necessary technology to look over something that was microscopic. -
Dalton Model (John Dalton) 1766 - 1871
English chemistry that propose the first atomic model in 1803. The model represent the atom as a solid ball of matter that is invisible with no parts. The Atom of the same elements have the same masses, and the atom of different elements have different masses; it also represent that the different elements atom combine for a compound. -
Goldstain (1850-1930)
He was a German neurologist and psychiatrist who created a holistic theory of the organism. Goldstein concluded that in addition to the electrons, or cathode rays, that travel from the negatively charged cathode toward the positively charged anode, there is another ray that travels in the opposite direction, from the anode toward the cathode. -
J.J Thompson´s Model "Plum Pluming" (Joseph John Thompson) 1856 - 1940
English scientist that discover the Atoms in 1897. This model was also called the “Plum Pudding”. This model represent the atom as a positively charged mass with electrons scattered through it; according to this model they would need to be ton of electron in an atom to balance the positive charge to the rest of the atom. When they made the experiment they notice that there were not that many electrons; so this model fail. -
Rutherford´s Planetarty Model (Ernest Rutherford) 1871 - 1937
Danids scientist that propose the the Planetary Model in 1913. This model represent the atom so similar to our solar system, with the electrons orbiting the nucleus as the planets do to the sun. According to this model the electron should be accelerating as they orbit the nucleus; this should make them create electromagnetic and tis would make them lose energy. This model didn't work so this model fail too. -
Borh´s Postulate (Niels Bohr) 1885 - 1962
In 1913 he developed his model. First he stated that the electrons describe orbits to the nucleus of the atom without irradiating energy. Then he states that the unic orbits allowed to an electron are those for which the angular moment, of the electron be an entire multiple from, L, from the electron a hole multiple of h=h/2π. The third postulate is that the electron only absorbs energy in the jump from one orbit to another. It emits a photon which energy is the differnece for both levels. -
James Chadwick 1891-1975
He work with Rurtherford and discover the particles with no charge; he called this particles neutron and say they were founf in the nucleus.
