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Democritus picture of his atomic model
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Aristotle
He was born in 384 PC and died in 322 BC and lived in Ancient Greece. Aristotle was a philosopher and did not believe in the atomic theory. His thoughts were that all substances were made of the four elements; Earth, Fire, Water, and Air. After this most people followed his theory than Democritus's atomic theory -
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Picture of his theory of the four elements
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Democritus
Born in 460 BC and died in 370 BC and lived in Ancient Greece. Democritus answered that all matter consists of ïnvisible"particles called atoms. He claimed that atoms are indestructible, He had the first atomic theory and model. His discovery helped people with the understanding of an atom and helped future scientists look more into the atom -
John Dalton
John Dalton was born on September 6, 1766 and died on July 27, 1844. He lived and worked in England.He was known as "Father of the Atomic Theory". In Dalton's Atomic Theory he claimed that, Elements are made by tiny particles called atoms. All atoms of a given element are identical. All atoms of different elements are different -
Dalton
John Dalton did his observations of his atomic theory from this time to when he died in 1844 -
Bohr's atom
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Niels Bohr
He was born on October 7, 1885. He is known as Father of modern atomic theory. He experimented with Hydrogen spectrums. He did a planatary model. He started working on his model aat around 1913. He got to discover this after he became head on Institute for Theoretical Physics. He died on November 18, 1962 -
diagram of the Plum Pudding model
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J.J. Thomson
He was born on December 18, 1856. Around the 1890's he did the Cathode Ray Tube experiment. This experiment showed that the atom has a negative piece in it. He is the founder of the electron. He used a Plum Pudding model to explain the electrons in an atom. He died on August 30, 1940 -
Chadiwck's model of what he thought the atom looked like with his discovery
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James Chadwick
He was born on October 20, 1891. He discovered the neutron, while working under Rutherford in 1932. Before his discovery scientists only knew about the proton and the nucleus. He helped modern scientists's understanding of the atom. Chadwick died on July 24, 1974 -
Marie and Pierre Curie
Marie was born in Polan on November 7, 1867. Pierre was born on May 15, 1859. They are most known for their study on radioactivity. Their discovery was in 1898. After Pierre died on April 19, 1906, Marie still taught as a general professor of physics, She was the first woman to hold this kind of position.Their discoveries together led to the modern understanding of the atom. Sadly Marie died on July 3, 1934 -
The curies model
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Millikan's oil drop experiment
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Robert Millikan
He was born on March 22, 1868. He found the negative charge. His work was the oil drop experiment. In this experiment he prooved Thomson's theory that the mass of an electron is at least 1000 times smaller than the smallest atom. He died on December 19, 1953 -
Ernest Rutherford
He was born on August 30, 1871. He discovered the nucleus, which was and is described as the center and is very dense. His model was the e- cloud model. He died on October 19, 1937. His discovery helped future scientists on what more was in an atom. -
Rutherfords model
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Henri Becquerel's model of radioactivity
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Henri Becquerel
He was born on Demember 15, 1952. He discovered radioactivity. This discovery later helped scientists to improve the atomic model. His famous experiment was done in Feb. of 1896. This experiment helped scientists learn more about radioactivity. He died on August 25, 1908 -
Quantum model
His model is the atomic model we use today by our modern scientist. Many scientists contributed to this.
