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Oct 27, 1000
democritus
Born 460 BC
Thought that atoms are not all the same, they are always moving. He said all matter is made up of invisible tiny things that cannot be seen by the eye. He thought that the solidness of a material was due to the shape of the atom involved. Iron had strong, solid atoms. Water had smooth, and slippery atoms. -
Oct 31, 1000
Aristotle
384 BC
He found 4 elements, fire, water, earth and air. He also came up with the theory of motion. -
John Dalton
Proposed the Atomic theory. He found atomic weight, and chemical symbols.He tested gases and used evaporation to find out what the gases had on the mixture all together. -
J.J. Thomson
credited for the discovery of the electon and of isotopes, and the invention of the mass spectrometer. He found electrons and subatomic particles when he was working with cathode ray tubes. He was working with glass tubes and electricity, and messed up and discovered electrons. -
Max Planck
He came up with the original quantum theory. To come up with this, all he did was research from previous scientists and a little bit on his own. He wrote a book on the Quantum theory. The book showed the behavior or matter and energy in an atom. he also made a math equation to help with his theory. -
Hantaro Nagaoka
He developed an incorrect planetary model of the atom.The model was based on an analogy to explain how stable the rings of Saturn were. He claimed it was stable due to a large nucleus, and electrons revolved around the nucleus.Other parts of his model were incorrect. -
Ernest Rutherford
He was able to ionize gas using radiation, and found alpha and beta waves. He used this research and the magnetic properties of iron to find radio waves. He discovered the nucleus by using other scientists findings. -
Hans Geiger
He helped to invent the Geiger counter and the Geiger-Marsden experiment led him to discovery of the atomic nucelus. The counter was able to prove The Compton effect, because it detected the neutrons, electrons, and quanta. -
Niels Bohr
Figured out the structure of the atom, and their radiations. He started the basis for the Quantum theory. He also developed the principle of compementarity, items can be seperately analyzed as having several contradictory properties. -
Erwin Schrodinger
He contributed to wave mechanics and quantum mechanics. He wrote many papers on wave energy and quantum mechanics. Many of his papers had a great impact on the physics community -
Ernest Marsden
Conducted the Geiger-Marsden experiment called the gold foil experiment in 1909 with han Geiger under Rutherford's leadership. -
James Chadwick
He discovred the existence of the neutron. He used alpha waves to find this, saying there was no charge in the neutron. He used an experiment similar to this to help with the creation of the atomic bomb. -
Louis de Broglie
He introduced his theory of electron waves. Which states that any moving particle or object had an associated wave.Created a new field of physics uniting energy waves and matter particles.
