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John Dalton
Dalton created the Atomic theory. He created 3 Laws, the law of multiple proportions: if you combine 2 or more elements together to form more then one compound, then the ratios of the masses of the 2nd element which combine with a fixed mass of the 1st element will be ratios of small whole numbers. The Law of definate composition states: a compound containss 2 or more elements combined in a definite proportion by mass. The law of conservation of mass that mass cant be created or destroyed. -
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J.J. Thompson
Invented the Raisin Bread Theory, body of the atom is spherical object containing electrons confined in a jelly like substance but has a positive charge to hold the electrons. -
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Max Planck
Quantum Theory, explains world on smallest scale, by stucture and behavior of atoms and subatomic particles. 1900 : E= h*f E depends on frequency, f= frequency in hertz, h= plancks constant : 6.63*10^-34 j-s.
Photoelectric efffect, certain frequencies of light knock electrons loose from atoms. Wave particle dualiuty: light is a wave and a particle. -
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Hantaro Nagaoka
First to present the Saturnian atomic model. Bohr model agreed with this model. -
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Robert Millikan
Invented the Oil Drop experiment. negatively charged oil drops could be suspended between charged plates. he calculated the mass of an electron. -
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Lord Earnest Rutherford
He delt with radioactive elements, discovered half lives of elements. alpha and beta rays discovered the proton and first to make a neuclear reaction. -
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Niels Bohr
Created a new model from rutherfords model. Called the Bohr model neucleus with electrons orbiting. -
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Erwin Schrodinger
Invented the Quantum Mechanical Model which is a model of the atomic structure and is based on mathmatics and is more accurate then other models. Based on theory that states matter had properties relating with waves called the quantum theory. -
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James Chadwick
Chadwick discovered the Neutron. -
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Louis De Brogile
De Broglies theory showed light was both a wave and a particle, by his equation c=hv -
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Heisenberg
Uncertainty principle, you cant be sure of all characteristics (vectors, speed, spin, mass) of a subatomic particle at the same time only a probability of that bein the case. -
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The Greeks
Empedolcles (492-432) All things made of 4 elements, Earth fire water and air. Leucippus(480-420) 2 diff elements, full and solid or empty and void. Theory of atomism- and infinate number of atoms exist and are resposible for the special properties of matter. Democritus(460-370) produced atomism to say that atoms were solid bodies infinate in number size and shape but still not large enough to see with the naked eye, everything emitted small films of atoms and were sensations. -
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The Greeks contin.
Plato (428-346) Founded the Academy - philosopher school. Used Empedocles element theory, identified each element with a regular solid, fire= tetrahedon air- octahedron water- icosahedron earth-cube. all properties of matter could be deduced through pure thought without experiments.
Aristotle (384-322) Studied under plato believed all objects were composed of a potential (matter) and reality (form) universe had no beginning or end, it was eternal.