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Antoine Lavoiser
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Antoine Lavoiser is a French biologist and chemist who dicovered the Law of Conservation (law states that matter cannot be made of destroyed) by turning HgO to Hg+O. -
John Dalton
He published his atomi theory which most still hold true today and was the foundation of the atomic theory in chemistry.
Dalton's Atomic Theory:
1) All matter is made of atoms. Atoms are indivisible and indestructable
2) All atoms of a given element are identical in mass and property
3) Compounds are formed by combinations of two or more different kinds of atoms
4) A chemical reaction is a rearrangement atoms
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Joseph Proust
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He published the law of definite proportions stating that when compounds are analyzed into their constituent parts they always contain the same proportionsof their elements by weight. -
William Crookes
Source Wlliam Crookes developed a better vacuum pump that allowed him to produce cathode ray tubes with asmal residual gas pressure. The cathode rays are negavitely charged y studying deflection of cathode rays by magnetic fields. -
JJ Thomsom
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Thompon identified the exxistance of the electron by studyng properties of cathode rays. His theory stated that atoms were spherical and had a positive charge. He also created the Plum Puding model in 1907 before the discovery of the nucleus by Rutherford. -
Max Planck
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Planck is the originator of the Quantum theory. His work in thermodynamic led to the Quantum theory. To explain colors of hot glowing matter, propesedengeny is radialed in very minute and discrete quantized amounts, rather than a continous broken waves. -
Marie Curie
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Marie and her husband, Pierre, discovered the radioactive elements polonium and radium in the pure state to prove the atoms of one element were not indivisable. They also studied Uranium and Thorium and call their spontaneous decay "radioactivity". -
Albert Einstein
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He was the first perosn to show a way to prove the existance of the atom. Then he also formulated the special theory of relativity. -
Ernie Rutherford
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Rutherford stated the atom has a central positive nucleus surrounded by negative orbiting electrons. He shot radioactive particles through gold foil. Some went straight through while 1 out of 8000 didn't proving there was something positive in the center of the atom. -
Neils Bohr
SourceBohrs greatest contribution was the atomic model (shows the atom small, positively charged nucleus surrounded by orbiting electrons. He discovred electrons travel in seperate orbits around the nucleus and the number of electrons in the outer orbit determines the properties of an element. He also developed the liquid droplet theory (a liquid drop provides an accurate representation of an atoms nucleus) and helped understand nuclear fission. -
Period: to
World War 1
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Fredrich Hund
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Made Hunds Rule which states that orbitals of equal energy are each occupied by one electron before any orbitals are occupied by a second electron, and all electron in singly occupied orbitals must have the same spin. This constraints placed on the way the atomic orbitals are filled by using the Aufbau Principle (sates that electrons occupy the lowest energy orbitala that can recieve it), -
Erwin Schroedinger
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He used mathematics equations to describe the likelyhood of finding an electron in a certain position. He also created Quantum Mechanical Model which predicts the odds of the location of the electron. -
Werner Heiesenberg
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He is known for his uncertainty principle which states the exact location and energy of an electron cannot be determined simultaneously. Finding one value means that there will be some uncertainity when finding the other value. -
Louis de Broglie
SourceBroglie discovered the wave nature of electrons. He discovered the electrons can act like wave and that the waves produeed by electrons contained in the orbit around the nucleus, set up a standing wave of a certain evergy, frequency, and wave length. -
James Chadwick
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Chadwick discovered the existance of a neutron. He used experiments of tracking particle radiation of Frederic and Irene Joliot-Curie to successfully discorver the neutron. -
Period: to
Hilter's Reigh
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Period: to
World War 2
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When the Atomic Bom Dropped
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Murray Gell-Mann and George Zweig
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They brought forth the idea of "quarks" little bits of matter which when used kind of like building bloks, serve to explain some complex chemical substance.
