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26 Cards in this Set
- Front
- Back
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When was Dalton's model of the atom created? |
1800 |
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Who's model of the atom looks like a circle? |
Dalton |
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Who discovered the electron? When? |
J. J. Thomson, 1897 |
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How did Thomson discover the electron's existence? |
through a series of experiments using a high-vaccuum cathode ray tube |
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Who discovered the proton? |
Ernest Rutherford |
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When was the proton discovered? |
1911 |
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Why did scientists assume that a positive particle existed? |
there had to be a positive particle to balance out the negative electrons |
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What particle was discovered through the gold foil experiment? |
protons |
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What was Rutherford's conclusion after the gold foil experiment? |
the atom is mostly empty space, and the mass is concentrated in the centre of the atom. |
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What was the oil drop experiment? |
observing tiny droplets of oil between two horizontal metal electrodes |
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What did the oil drop experiment prove? |
it measured the elementary electric charge (the charge of an electron) |
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What experiment was conducted by Robert Milikan and Harvey Fletcher? |
the oil drop experiment |
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Who's model of the atom was given the name "plum pudding"? |
J. J. Thomson |
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When was Thomson's plum pudding model created? |
1897 |
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Why was a new model necessary during Thomson's time? |
because of new discoveries having been made, such as the existence of electrons |
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Who's model of the atom looked like a chocolate chip cookie? |
Thomson |
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Were the chocolate chips in Thomson's model negative particles or positive particles? |
negative (electrons) |
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Were there protons in Thomson's model of the atom? |
no, it was composed of positively charged material with electrons scattered around in it |
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What did Rutherford expect to happen during the gold foil experiment? |
he expected the alpha particles to go straight through the foil |
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What actually happened during the gold foil experiment? |
some particles went through, but a majority bounced off of the nuclei, (bouncing off the positive part of the atom) causing them to change directions |
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Who's model of the atom was the first to include a nucleus? |
Rutherford's model |
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Who's model of the atom is sometimes called the planetary model? |
Bohr |
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When did Bohr create his model of the atom? |
1913 |
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Who were the 6 scientists who discovered the neutron? |
Walter Bothe, Herbert Becker, Irene Joliot-Curie, Frederic Joliot, Ettore Majorana, James Chadwick |
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Who was given credit for the discovery of the neutron? |
James Chadwick |
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How was the neutron discovered? |
He aimed radiation at protons, measured the range and how the new radiation impacted atoms of various gases. He found out that radiation wasn't caused by alpha rays, but rather by "uncharged particles" that had the same mass as protons!! (neutrons!!) |
