MK

Physical Science - Chapter 8

Nuclear Changes

8A Radioactive Decay

  • ^^Nuclear Change^^: any change that alters the composition of the nucleus in an atom

Discovering Radioactivity

  • ^^X-ray^^: used for medical imagery, transportation security, and nondestructive inspection

  • ^^Radioactive Decay^^: the naturally occurring, spontaneous change of an unstable isotope to a more stable one by emitting particles or energy or both

  • ^^Strong Force^^: an attractive force that holds protons and neutrons together in a nucleus

  • Types of Radioactive Decay

    • ^^Alpha Decay^^: a nuclear decay that results in the emission of an alpha particle
    • ^^Beta Decay^^: a nuclear decay that results in the emission of a beta particle
    • ^^Gamma Decay^^: a nuclear decay that results in the emission of gamma rays

  • ^^Half-life^^: the time in which half the atoms of a radioactive sample will probably decay

8B: Fission and Fusion

  • ^^artificial transmutation^^: a manmade artificial change

  • Fission

    • ^^fission^^: a nuclear reaction in which a large nucleus splits into smaller nuclei
    • ^^chain reaction^^: a self-sustaining nuclear fission process in which neutrons produced in one fission reaction trigger more fission events
    • ^^critical mass^^: the smallest mass of fissionable material that can sustain a chain reaction

  • ^^fusion^^: a nuclear reaction in which small nuclei combine to form a more massive nucleus

8C: Nuclear Changes - Benefits and Risks

  • Using Radiation
    • ^^radiotracer^^: a radioactive isotope used in nuclear medicine to study how an isotope moves through or collects in a certain way
  • Effects of Radiation
    • ^^ionizing radiation^^: radiation that is energetic enough to knock electrons out of atoms or molecules; most damaging to living organisms
    • ^^somatic damage^^: any damage to cells that are not involved in reproduction, thus harming the organism but not any future offspring
    • ^^genetic damage^^: any damage done to DNA in cells that can affect growth and reproduction of the cells; can be passed to offspring if it occurs in reproductive cells
  • Detecting Radiation
    • ^^Geiger counter^^: a device designed to measure ionizing radiation
    • ^^dosimeter^^: a device used to measure exposure to radiation