Chapter 4 Chemistry: Matter and Change (Study Guide) – Flashcards
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Alpha Radiation
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is deflected toward a negatively charged plate when radiation from a radioactive source is directed between two electrically charged plates.
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Atom
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smallest particle of an element that retains the properties of the element.
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Atomic Mass
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weighted average mass of the isotopes of that element.
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Atomic Mass Unit
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one-twelfth of the mass of a carbon-12 atom.
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Beta Radiation
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is deflected toward a positively charged plate when radiation from a radioactive source is directed between two electrically charged plates.
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Cathode Ray
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a ray of radiation that originates from the cathode and travels to the anode of a cathode ray tube
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Dalton's Atomic Theory
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based on numerous scientific experiments, that marked the beginning of the development of modern atomic theory.
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Gamma Ray
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high energy radiation that has no electrical charge and no mass, is not deflected by electric or magnetic fields, usually accompanies alpha and beta radiation, and accounts for most of the energy lost during radioactive decay.
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Isotopes
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atoms of the same element with the same number of protons but different numbers of neutrons.
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Nucleus
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the extremely small, positively charged, dense center of an atom that contains positively charged protons, neutral neutrons, and is surrounded by empty space through which one or more negatively charged electrons move.
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Radiation
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rays and particles--alpha and beta particles and gamma rays--that are emitted by radioactive materials.
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Radioactive Decay
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a spontaneous process in which unstable nuclei lose energy by emitting radiation.
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Radioactivity
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the process in which some substances spontaneously emit radiation.
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Both pertain atoms; Mass number is the sum of protons & neutrons in the nucleus, Atomic number is the number or protons in an atom.
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Mass number, Atomic Number (Compare & Contrast)
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Both concern changes in an atom; Nuclear reaction involves change in an atom's nucleus, Nuclear equation shows the atomic number & mass number of the particle involved in a reaction.
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Nuclear Reaction, Nuclear Equation (Compare & Contrast)
