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23 Cards in this Set
- Front
- Back
Roentgen Experiment
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blocked cathode ray and pointed it at materials - they flouresced
-learned about "x-rays" and even if you can't see E emitted, radiation is still there |
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Becquerel Experiment
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placed flour'nt mineral crystals on photographic plate in black paper - minerals gave off E
-discovered radioactivity |
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Rutherford - alpha, beta, gamma Experiment
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placed thin Al sheets in path of U radiation and used magnets to bend beams
-discovered alpha, beta, and gamma radiation |
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Rutherford - Gold Foil Experiment
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focused beam of alpha particles on sheets of gold foil - some passed through & others bounced back
1) most of V of atom is empty space 2) has very dense nucleus |
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Marie & Pierre Curie
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attempted to isolate radioactive component of pitchblende
-discovered Polonium and Radium (all U components are radioactive) |
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radioactivity
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spontaneous emission of nuclear radiation
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unstable nuclei
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radioactive nuclei with too many protons or too many neutrons (a radioisotope)
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ionizing radiation
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carries more energy that can eject electrons from atoms/molecules forming molecular fragments/ions
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isotopic notation
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from right to left: mass number on top, atomic number on bottom; element symbol; charge
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annual radiation dose
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5000mrem for people working with radiation, 500mrem otherwise, average exposure is 360mrem
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alpha particles
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largest nucleus (helium atom), stopped by skin (slowest form), positive charge
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nuclear radiation
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spontaneous injection of radiation from particles in atom
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beta particles
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equivalent to electron (1/1837amu), fast, can pass through skin, negative charge
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gamma rays
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pure E (no mass or charge), can pass farthest through skin, travel at speed of light
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background radiation
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the radiation that is naturally in the environment every day
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Artificial Radiation - Ernest Rutherford Equations
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Rutherford placed N gas in glass tube, bombarded it with alpha particles - found that some of N had converted to O isotope (hydrogen atom also produced)
-he performed first artificial transmutation |
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transmutation
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conversion of one element to another naturally or artificially
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Irene & Frederic Joilet-Curie
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bombarded Al with alpha particles producing Phosphorus-30, first artificial radioactive isotope
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Know how to identify (1) target nucleus, (2) projectile, (3) product nucleus, (4) ejected particle in a bombardment reaction.
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REACTANTS: (1) larger atom, (2) smaller atom; PRODUCTS: (3) larger atom, (4) smaller atom
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transuranium
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elements with larger mass than uranium (later added to table in lanthanide & actinide series)
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synthetic nuclei
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atoms that have been artificially created (transuranium elements)
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tracer studies
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Tc-99m - measures cardiac output, locates strokes and brain/bone tumors; Ga-67 - diagnoses Hodgkin's disease; I-123 - diagnoses thyroid gland problems; Radiosodium-24 - locates abnormalities in circulatory system
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irradiation
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1) medical - Cs-137 - treats shallow turmors; P-32 - treats leukemia; I-131 - treats thyroid cancer
2) industrial - irradiation of food (can output a lot of radiation) |