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13 Cards in this Set
- Front
- Back
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Einstein
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e=mc2 -special theory of relativity: energy can be converted into mass and mass can be converted into energy. -light could be treated as waves or particles
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Dalton
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-the first modern scientist to propose the existence of atoms. He described an atom as an invisible, indestructible, solid sphere, like a billiard ball. -Dalton's atomic theory.
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Democritus
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-proposed that matter cannot be broken down indefinitely. At some point you end nup with a piece that cannot be divided. That smallest piece he called an atom, from the Greek word atoms, which means "indivisible."
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Thomson
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-proposed the "plum-pudding" model: an atom is a solid mass of positively charged material with negative charges scattered through it like pieces of plums in pudding. He is credited with discovering the electron with a cathode ray tube.
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Chadwick
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-discovered neutrons.
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Millikan
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-used the oil-drop apparatus shown to determine the charge and mass of an electron
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Bohr
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-proposed that electrons move in different orbits, or energy levels, around the nucleus like planets orbit the sun. Each energy level is located a specific distance from the nucleus and contains a certain number of electrons.
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The Curies
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-first noticed radioactivity. -helped develop the field of nuclear chemistry. - identified polonium and radium.
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Rutherford
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-proved that atoms are mostly empty space. Discovered the nucleus, which contains positively charged particles. Was the first to suggest that electrons circle the dense nucleus.
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Heisenberg
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-showed it is impossible to take any measurement of an object without disturbing it. -Heisenberg uncertainty principle: states it's fundamentally impossible to know both the velocity and position of a particle at the same time.
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Schrodinger
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-treated electrons as waves in the quantum mechanical model of the atom ( current model. )
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de Broglie
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-said that particles, including e-, could have wavelike behaviors -the de Broglie equation: predicts that all moving particles have wave characteristics
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Pauli Exclusion
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-no two e- can have the same 4 quantam numbers. -e- in the same orbital must have different spins: +1/2 or -1/2 in a magnetic field
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