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49 Cards in this Set
- Front
- Back
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What is radiation?
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the emission of energetic particles
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Nuclear chemistry is the study of...
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radiation
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Nuclear chemistry often results in...
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one element changing to another
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Details on Chernobyl
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April 26, 1986-- 1:24am
explosion in reactor 4 31 deaths, 230 hospitalizations |
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Contrast ordinary chemistry and nuclear chemistry in terms of what changes are involved.
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ordinary- electrons change
nuclear- nuclei change |
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What did Bequerrel initially discover?
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his paper-wrapped photographic plate was exposed by uranium-containing crystals
--disproving his hypothesis |
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What was Bequerrel's hypothesis?
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he linked exposure to UV light and phosphorence
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What did Bequerrel discover secondly?
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a brand new phenomenon which he called uranic rays
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What did Curie discover?
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two new emitters of uranic rays, one an element- polonium
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What did Curie's discovery prove about uranic rays?
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that they were not unique to uranium and therefore radioactivity was coined
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Radioactivity was characterized by...
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Rutherford
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Radioactivity is the result of...
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nuclear instability
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Alpha- description, symbol, ionizing/ penetrating power
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Helium nucleus, 4/2 He, high ionizing power, low penetrating power
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Beta- description, symbol, ionizing/ penetrating power
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electron, 0/-1 e, moderate both
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Gamma- description, symbol, ionizing/ penetrating power
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high energy photon, 0/0 y, low ionizing, high penetrating
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Alpha radiation is composed of...
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two proton and two neutrons
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Compared to alpha particles, beta particles are...
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smaller so more penetrating but less ionizing
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What is gamma radiation?
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an energetic photon emitted by an atomic nucleus
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Characterize gamma rays.
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electromagnetic, not matter
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What is half-life?
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the time it takes for half of the nuclei in a sample to decay
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What is the general idea behind nuclear fission?
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if nuclei emit particles to form lighter elements, they might also absorb particles to form heavier elements
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The result of nuclear fission would be...
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a synthetic element
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What element was Fermi going to use in an attempt to make a synthetic element?
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#93- neptonium
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What did Fermi detect in his experiments?
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beta emission following his neutron bombardment of uranium
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What puzzling evidence was revealed about Fermi's experiments by other scientists before WWII?
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that the result was two lighter elements-- no heavy element was detected
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What did scientists do about the alarming evidence that was revealed right before WWII?
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did an experiment which contradicted all previous ones in nuclear physics
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What was this new experiment?
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they proposed a model for the fission of uranium atoms on absorption of neutrons
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What else was emitted during the new experiment during fission?
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large amounts of energy
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What did the new experiment lead to?
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the production of U-235, could be either a basis for a chain reaction or a bomb of "inconceivable power"
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What was the motivation behind the Manhattan Project?
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Albert Einstein communicated the fact that Germany was trying to make a fission bomb to Roosevelt- the race was on
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Who constructed the first nuclear reactor and where?
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Fermi and Szilard, at U of Chicago
-it lasted 4.5 minutes |
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After the successful controlled reaction, what was the goal?
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construction of a device where fission would spiral out of control
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What two locations in the US were designated for collection of U-235 and Pu-239?
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Oak Ridge, TN
Hanford, WA |
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Where was the bomb designed?
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Los Alamos, NM
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How are bombs designed?
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fission escalates and produces an explosion
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Nuclear reactors are designed to produce...
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a controlled fission reaction
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Uranium rods usually have one of what two elements in them because they absorb neutrons?
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boron or cadmium
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What produces electricity in the turbines?
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heat of fission boils water to produce steam, which turns the turbine and produces electricity
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Nuclear Burning
how much per day? how many people? advantages? disadvantages? |
100 lb of fuel per day to power 1 million people
a: does not produce pollution, greenhouse gases, acid rain da: waste disposal, accidents |
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Coal-burning uses...
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5 million pounds of fuel for the same amount of energy
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How often are uranium oxide pellet fuel assemblies replaced?
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every 18 months
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What did the Nuclear Waste Policy Act do? When?
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1982
established a program to build an underground waste depository |
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Where was the Nuclear Waste Policy act supposed to take place?
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Yucca Mountain, NV
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Why can nuclear power plants not explode like actual nuclear bombs?
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3% enriched uranium vs. 90% enriched uranium
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What is mass defect?
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difference between the experimentally measured mass of an atom and the sum of the masses individually measured protons, neutrons, and electrons
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Where did the missing mass go that happens during mass defect?
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converted to energy
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Mass defect is closely related to what equation?
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E=MC2
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E=MC2 represents
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the energy that holds a nucleus together
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This binding energy is highest for what elements?
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close to mass # 56
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